NNFLfile:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... JNTU ONLINE EXAMINATIONS [Mid 2 - NNFL] 1. The weight updation in extended delta rule is a. ∆Wi=α (tj-yj)xi f. (y-in j) b. ∆W ij=α (tj-yj) f (y-in j) c. ∆W ij= xi f. (y-in j) d. ∆W ij=α(tj-yj)xi 2. The squared error for particular training pattern if extended delta rule is a. Ε=Σ m j=1 (t j-yj)2 b. Ε=Σ m j=1 (tj+yj)2 c. Ε=Σ mj=1 (tj)2 d. Ε=Σ m j=1 (yj)2 3. The connection matrix W= a. b. c. d. k=1..a ΣAk Bk T k=1..a ΣA k k=1..a ΣB k T k=1..aΣA kB k 4. The Auto associative net training is often called as a. Storing the vectors b. Sorting the vectors c. Recalling the vectors d. Searching for the vectors 5. Two vectors a and b are orthogonal if a. Σi ai=0 b. Σi b i=0 c. Σ i ai bi =0 d. Σi ai b i =1 6. The following rule allows for an arbitrary differentiable activation function to be applied to the output units a. Delta b. Extended Delta c. Hebb d. Hopfield 7. The updation of the following is done to reduce the difference between the computed output and the target a. Input b. Output c. Target d. Weight 8. Representation of data (-1,+1) is called a. Bipolar b. Binary c. Real valued d. Bilinear 9. The performance of the auto associative memory net is among the following for bipolar vectors than the binary vectors a. Worst b. Better c. Equal d. No way related 10. Important criterion for an associative network is among the following it can store a. Time to train b. Number of patterns c. Iterations d. Zero elements 11. The following rule can be used for both binary as well as bipolar vectors a. Hebb rule b. LVQ 1 of 21 10/16/2011 9:31 AM NNFL file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... c. LMS d. Winner Rule 12. The weight determination formula in associative memory is a. W=Σ p=1..p ST (p) t(p) b. W=Σp=1..p S (p) t(p) c. W=Σp=1..p ST (p) d. W=Σp=1..p t(p) 13. The following rule changes the weight of the connection to minimize the difference between the net input to the output units and the target value a. Delta Rule b. Hebb Rule c. LMS Rule d. Adaline 14. The following energy points of the Lyapunov surface have to be mapped to desired memory states a. Maximum b. Minimum c. Zero d. Only one 15. The connection matrix W= a. k=1..a ΣAk Bk T b. k=1..a ΣA k c. k=1..a Σ B k T d. k=1..a ΣA k B k 16. The following matrix provides a way to encode associations as memories into a neural network a. Hebb matrix b. Covariance matrix c. Bilinear matrix d. Inverse matrix 17. The following results if the input vector pair is same as the output vector pair a. Auto associative b. Hetero associative c. Bidirectional Memories d. Self organizing maps 18. The following results if the input vector pair is different as the output vector pair a. Auto associative b. Hetero associative c. Bidirectional Memories d. Self organizing maps 19. The following rule for pattern association is an iterative learning rule a. Delta Rule b. Hebb Rule c. LMS Rule d. Adaline 20. The Delta Rule for single output unit is given by a. ∆Wj=α(t-yin)xi b. ∆W j=α(t-yin) c. ∆W j= (t-yin)xi d. ∆W j=α(yin)xi 21. When an axon of cells excite(s) cell B and repeatedly or persistently takes part in firing it, some growth process or metabolic change takes place in one or both cells so that A s efficacy as one of the cells firing B is a. Increased b. Decreased c. Equal d. No way related 22. The following is process of forming association between related patterns a. Pattern Association b. Pattern Classification c. Pattern Recognition d. Pattern Clustering 2 of 21 10/16/2011 9:31 AM NNFL file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... 23. The following nets are single layer nets in which the weights are determined to store an asset of pattern association a. Hopfield b. Associative Memory c. Boltzmann's Machine d. Perceptron 24. The simple and frequently used method for determining the weights for an associative memory neural net is a. Hebb rule b. LVQ c. LMS d. Winner Rule 25. The following rule assumes that the error signal is directly measurable a. Delta Rule b. Hebb Rule c. LMS Rule d. Adaline 26. The Delta Rule for single output unit is given by a. ∆Wj=α(t-yin)xi b. ∆W j=α(t-yin) c. ∆W j= (t-yin)xi d. ∆W j=α(yin)xi 27. The Delta Rule for several output units is given by a. ∆W ij=α(tj-yinj)xi b. ∆W ij=α(tjxi c. ∆W ij= (tj-yinj)xi d. ∆W ij=αxi 28. Whether the system is auto associative or hetero associative, the following that are to be associated is store d in connections of the network a. Input b. Memory c. Output d. Control 29. Following memories can be used as one shot memories a. OLAM b. BAM c. CAM d. ART 30. The following has the restrictions on the maximum number of associations it can accurately recall a. ART1 b. BAM c. ART2 d. Hopfield network 31. The following BAM is implemented by interconnecting neurons within each layer by means of additional weights a. Continuous b. Discrete c. Adaptive d. Competitive 32. The accretive associative memory is called a. Auto associative memory b. Hetero associative memory c. Hybrid associative memory d. Hopfield network 33. The following is a system that provides a mapping from a domain of inputs to a range outputs a. Fundamental memory b. Main memory c. Additional memory d. Associative memory 34. In associative memory if xk is the input and yk is the output, and when xk ≠ yk the process is known as a. Auto associative b. No associative 3 of 21 10/16/2011 9:31 AM NNFL file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... c. Heteroassociative d. Biassociative 35. The following types of BAM are stable a. Continuous b. Discrete c. Adaptive d. Competitive 36. The following network accepts an input vector on one set of neurons and produces a related but different output vector on another set a. Hopfield b. BAM c. Boltzmann's machine d. ART1 37. All BAM's are unconditionally stable for any weight network was proposed by a. Kosko b. Rumelhart c. McCulloh Pitts d. Kohonen 38. In the following system, any neuron is free to change state at any time a. synchronous b. asynchronous c. linear d. nonlinear 39. The Bidirectional Associative Memory (BAM) has a neural network of two layers connected with the following system a. Unidirectional b. Parallel c. Feedback d. Feed forward 40. The BAM a. b. c. d. is a the following network auto associative Non-associative Heteroassociative ART 41. When ∂E/∂t ≤0 the following is obtained a. Minima b. Maxima c. Focus point d. Trajectory 42. Energy function of continuous Hopfield net when � is a time constant is given as a. E = -0.5 i=1..m Σ j=1..mΣ W ij Vi Vj - Σθ i.Vi + (1/ τ) Σ j=1..m fi-1 (v)dv b. E = -0.25 i=1..m Σ j=1..mΣ W ij V i V j - Σθ i.V i + (1/ τ) Σ j=1m fi-1 (v)dv c. E = 0.5 i=1..m Σ j=1..mΣ W ij V i V j - Σθ i.V i + (1/ τ) Σ j=1..m fi-1 (v)dv d. E = 0.5 i=1..m Σ j=1..mΣ W ij V i V j - Σθ iV i + Σ j=1..mfi-1 (v)dv 43. In continuous Hopfield the energy function is a. E = 0.5 i=1..m Σ j=1..mΣ Wij Vi Vj + i=1..m Σθ i.Vi b. E = 0.5 i=1..m Σ j=1..mΣ W ij V i V j c. E = 0.5 i=1..m Σ j=1..m V i V j + i=1..m Σθ i.V i d. E = 0.5 i=1..m Σ j=1..mΣ Wij j + i=1..m Σ � i.V i 44. When the activity of each neuron is formed to change with time, the net is found to converge according to the following differential equation a. dU i /dt = -Ui/ τ + Σ j=1..m Wij Vj - θ j b. dUi /dt = -Ui + Σ j=1..mΣ W ij V j c. dUi /dt = -Ui/ τ + W ij V j d. dUi/dt = Σ j=1..mΣ W ij V j- θ j 45. The following matrix has the property Wij= Wji for i≠ j and Wij=0 for all i a. Unit matrix b. Symmetric matrix c. Sparse matrix d. Inverse matrix 46. Continuous valued output functions are used in 4 of 21 10/16/2011 9:31 AM NNFL file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... a. b. c. d. Discrete Hopfield Continuous Hopfield McCulloh Pitts ART-1 47. The connections between the units are bidirectional in a. BAM b. Discrete Hopfield c. McCulloh Pitts d. ART-2 48. The Hopfield net can be viewed as an a. Auto associative BAM b. Hetero associative BAM c. Boltzmann's machine d. McCulloh Pitts model 49. Diagonal a. b. c. d. elements of symmetrical weight matrix of BAM are 1 0 Non-zero Negative value only 50. Lack of the following connections ensure that the networks are conditionally stable a. Input b. Feed forward c. Feed backward d. Feed follow 51. In the following network an individual unit doesn t connect to itself a. Hopfield b. BAM c. Boltzmann's matrix d. ART1 52. a. b. c. d. 0 in the relation matrix if (x, y) ∈R Doesn't belongs to R 1 Equal composition T for relation matrix is defined as T ( x,z) = y ε Y Max ( Min (R (x,y), S(y,z))) T ( x,z) = y ε Y Min ( Min (R (x,y), S(y,z))) T ( x,z) = y ε Y Max ( Max (R (x,y), S(y,z))) T ( x,z) = y ε Y Min ( Max (R (x,y), S(y,z))) 53. R ( i,j) = a. b. c. d. 54. Max Min a. b. c. d. 55. If A1={a,b} A2={1,2} A3={α} then = a. b. c. d. 56. R ( i,j) = a. b. c. d. 1 in the relation matrix if (x, y) ∈R Doesn't belongs to R 1 Equal 57. If n= 5 the relation R (X1, X2) is termed as a. Binary b. Ternary c. Finite d. Quinary 58. If the universe of discourse or sets are finite, the n-ary relation can be expressed as an a. Resource Matrix b. Relation Matrix c. Region Matrix 5 of 21 10/16/2011 9:31 AM NNFL file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... d. Sparse Matrix 59. If R = {(x,y)/y=x+1, (x,y) X then R= a. {(1,3),(2,3),(3,5)} b. {(1,2),(2,3),(3,4)} c. {(1,1),(1,3),(0,4)} d. {(1,0),(2,0),(3,1)} 60. {(a,b)/a∈ A b∈B is a. A x B b. A ∪ B c. A∩ B d. A ∪ Bc 61. If A ≠ B and A and B are non empty then a. A x B = B x A b. A x B ≠ B x A c. A x B = θ d. Ax B = X 62. Composition of relation R and S are denoted by a. R o S b. S + R c. R ∪ S d. R - S 63. If A contains B then a. A is superset of B b. A is subset of B c. A is leader of B d. A is complement of B 64. The following set of set A is the set of all possible subsets that are derivable from A including Null set a. Power set b. Subset c. Superset d. Null set 65. If a set has no members then it is called a. Null set b. Non empty set c. Complement set d. Ideal set 66. A set with single element is called a. Hamilton b. Planar c. Euler d. Singleton 67. If A is fully contained in B then a. A is superset of B b. A is subset of B c. A is leader of B d. A is complement of B 68. The following set is the which, with reference to a particular context contains all possible elements having the same characteristics and from which sets can be formed a. Universe of discourse b. Complement c. Singleton set d. Null set 69. The following is well defined collection of objects a. UML diagrams b. Sets c. Venn diagram d. Figure 70. The following diagram is pictorial representations to denote a set a. Gannt chart b. DAG c. Venn diagram d. RAG 6 of 21 10/16/2011 9:31 AM NNFL file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... 71. An element is said to be if a belongs to set A a. Cardinal b. Member c. Sibling d. Child 72. The number of elements in a set is called a. Chromatic number b. Cardinality c. In degree d. Out degree 73. The equation of defuzzified value x ∗ in MOM defuzzification method is a. x ∗ = ( xi ∈M Σxi)/ b. x ∗ = ( xi ∈M-3 Σxi)/ c. x ∗ = ( xi ∈M+1 Σxi)/ d. x ∗= ( xi ∈M Σxi ) 74. For a discrete membership function, centre of area is a. x∗=i=1..n Σxi µ (xi) /( i=1..n Σ µ (xi) ) b. x∗ = µ (xi) /( i=1..n Σ µ (xi) ) c. x∗=i=1..n Σxi /( i=1..n Σ � (xi) ) d. x∗=i=1..n Σxi (xi) /( i=1..n Σ µ (xi) ) 75. For a discrete membership function, centre of area is a. x∗=i=1..n Σxi µ (xi) /( i=1..n Σ µ (xi) ) b. x∗ = µ (xi) /( i=1..n Σ µ (xi) ) c. x∗=i=1..n Σxi /( i=1..n Σ µ (xi) ) d. x∗=i=1..n Σxi (xi) /( i=1..n Σ µ (xi) ) 76. In case with more than one element having maximum value firing defuzzification, the following should be taken a. Mean value of maxima b. Mean value of minima c. Centroid d. Mode value 77. The following is the largest membership grade obtained by any element in that set a. Index b. Height c. Degree d. Member 78. In MOM defuzzification method in continuous case M could be defined as the following where |µ(x) is equal to height of fuzzy set a. M = { x∈ [-C,C] b. M = { x&isin [0,1] c. M = { x&isin [0,0] d. M = { x&isin [1,1] 79. In centre of sums method the defuzzified value x∗ is a. x∗ =i=1..N Σ xi k=1..N . Σµ� k xi/ (i=1..N Σ i k=1..N . Σµ� k xi) b. x ∗ =i=1..N Σ xi k=1..N . Σµ� k xi/ ( Σµ� k xi) c. x∗ =i=1..N Σ xi k=1..N . Σµ� k xi/ (i=1..N Σ i k=1..N . Σµ� k ) d. x* =i=1..N Σxi k=1..N . xi /(i=1..N Σ i k=1..N . Σµ� k xi) 80. A collection of rules referring to a particular system is known as a. Fuzzy database b. Fuzzy rule base c. Fuzzy set d. Fuzzy relation 81. Conversion of fuzzy set to single crisp value is called a. Fuzzification b. Defuzzification c. Crispification d. Decryptography 7 of 21 10/16/2011 9:31 AM NNFL file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... 82. Conversion of single crisp value to fuzzy set is called a. Fuzzification b. Defuzzification c. Crispification d. Decryptography 83. Most commonly used defuzzification method a. Centre of area b. Centre of sums c. Centre of gravity d. Mean of maxima 84. Number of times overlapping area is counted in centroid method is a. Only one b. Twice c. Thrice d. Doesn't count at all 85. Number of times overlapping area is counted in centre of sums method is a. Only one b. Twice c. Thrice d. Doesn't count at all 86. The energy function of discrete Hopfield network is a. E= -0.5 Σ i≠jΣ j yiyj w ij Σ xi yi + Σ Oi yj b. E= Σi≠j Σj yiyj wij Σ xi yi + Σ Oi yj c. E= -0.25 Σi≠j Σj yiyjwij Σ xi yi + Σ Oi yj d. E= -0.5 Σi≠j Σj yiyj wij Σ xi yj 87. ∆E = a. b. c. d. -[Σj (yj w ij + xi - θi∆yi] -[Σj (yj wij)∆yi] -[Σj (xi - θ i )∆yi ] -[Σj (yj wij + ∆yi ] 88. The essence of a CAM is to map the following onto a fixed (stable) point a. Output b. Fundamental memory c. Main memory d. Additional memory 89. The energy cannot increase for both positive and negative change in yi , the value of ∆E is a. less than zero b. Greater than zero c. Equal to zero d. Infinity 90. In the following mode of training, all neurons in Hopfield networks fire at random. a. Stable state b. Output c. Synchronous d. Asynchronous 91. The change in energy is due to a change in the a. Time of training b. State of neuron c. Number of neurons present d. Weight 92. If the energy doesn t change with further iteration then the net reaches a. State equilibrium b. State inequilibrium c. State annealing d. State instability 93. The formulation of the following nets shows the usefulness of net as a content addressable memory a. Discrete Hop b. Continuous Hop c. Discrete BAM d. Continuous BAM 94. The function is used to prove the stability of recurrent network a. Time 8 of 21 10/16/2011 9:31 AM NNFL file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... b. Energy c. Sigmoid d. Pressure 95. Four neurons have the following number of probable states. a. 8 b. 16 c. 32 d. 64 96. The fuzziness of the data can be decreased by a. Decreasing the weighting factor W b. Increasing the weighting factor W c. Doesn't change with weighting factor d. Keeping the weighting factor constant 97. The most famous fuzzy clustering procedure in the literature is a. k-means algorithm b. DB-scan algorithm c. Fuzzy-c-means algorithm d. Gaussian algorithm 98. The sum a. b. c. d. of memberships of all elements in a cluster is always 0 -1 1 Variable 99. The fuzziness of the data can be increased by a. Decreasing the weighting factor W b. Increasing the weighting factor W c. Doesn't change with weighting factor d. Keeping the weighting factor constant 100. Fuzzy clustering can also be termed as a. Overlapping clustering b. Exclusive clustering c. Hierarchical clustering d. Probabilistic clustering 101. Fuzzy Classification can be applied a. Only to Fuzzy Data b. Only to Crisp Data c. Can be applied to any type of Data d. Only to Graphical Data 102. The main advantage of Fuzzy Classification is a. Features in linguistic forms can be converted to Mathematical values b. Features can be modeled with probabilistic functions c. Features can be modeled directly with block diagram d. Features can be modeled graphically 103. Fuzzy classification is implemented using a. Only Crisp logic b. Only Fuzzy logic c. Both Crisp and Fuzzy logic d. Only Predicate Logic 104. The weighting factor W Accounts for the a. Fuzziness of data b. Exactness of data c. Probability of data d. Distinct nature of data 105. Biggest application of fuzzy classification is a. Data mining b. Image Processing c. Geographical information system d. Medical analysis 106. Limitation of fuzzy classification is a. Low dimensional data b. High dimensional data c. Trained data d. Uncertain data 9 of 21 10/16/2011 9:31 AM NNFL file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... 107. Half tea spoon sugar placed in tea implies a. Sweetness is 0.5 b. Probability of sweetness is 0.5 c. Sweetness feature can be modeled with a membership 0.5 d. Sweetness feature can be modeled with a membership 0.5 Sweetness is 0.5 108. The classes in fuzzy classification are a. Exact b. Distinct c. Distinct but overlapping d. Only overlapping 109. Fuzzy classification is a a. Decision based application b. Rule based application c. Branching application d. Both decision based and rule based 110. Fuzzy membership functions can be a. Only distinct b. Only continuous c. Only graphical d. Can be distinct and continuous 111. The output of the fuzzy classifier is determined by the rule which has a. Lowest degree of membership b. Highest degree of membership c. 0 degree membership d. Exactly 0.5 membership 112. The partitioning of data in fuzzy classification is usually carried by a. Clustering b. Probability c. Statistical analysis d. Regression 113. The goal a. b. c. d. of fuzzy classification is To cluster the data To find highest memberships To implement fuzzy logic To create category memberships 114. The use of fuzzy classification to ordinary classification is to get a. Fixed range of values b. Overlapping range of values c. Exact values d. Optimal values 115. Biggest application of fuzzy classification is a. Data mining b. Image Processing c. Geographical information system d. Medical analysis 116. If 0≤ µ � (x) then T (P∼) a. µ� (x) b. P c. 0 d. 1 117. B'∼= a. b. c. d. �' O X(x,y) �' U X(x,y) �' || X (x,y) �' 118. µB∼ c (y)= a. b. c. d. 119. Absolute fuzzy quantifiers are defined over 10 of 21 10/16/2011 9:31 AM NNFL file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... a. b. c. d. R 0 1 α 120. Fuzzy inference also referred to as a. Approximate reasoning b. Abductive reasoning c. Inductive reasoning d. Default logic 121. The following is a statement which acquires a fuzzy truth value a. Fuzzy preposition b. Fuzzy predicate c. Binary value d. Real value 122. GMP stands for a. Generalized Modus Ponens b. Generalized Modus Potent c. Generalized Modus Point d. Generalized Modus Potential 123. GMT stands for a. Generalized Modus Tag b. Generalized Modus Tollens c. Generalized Modus Thrice d. Generalized Modus Threat 124. µ (x,y) = a. b. c. d. µx (x,y) µx (x) µx (y) µ (x,y) 125. µ�*� (x,y)= a. Min(µ� (x), µ� (y)) b. Max(µ� (x), µ� (y)) c. Min(µ� (x),µ� (x)) d. Min(µ� (y), µ� (y)) 126. µ∪(x,y) = a. Max (µ (x,y), µ (x,y)) b. Min (µ (x,y), µ (x,y)) c. 1-µ (x,y) d. 1-µ (x,y) 127. µ∩ (x,y) = a. Max (µ X (x,y),µ (x,y)) b. Min (µ X (x,y), µ (x,y)) c. 1-µ (x,y) d. 1- µ (x,y) 128. µ c (x,y)= a. Max (µ (x,y), µ (x,y)) b. Min (µ (x,y), µ (x,y)) c. 1-µ (x,y) d. 1- µ (x,y) 129. The following is fuzzy set defined on Cartesian product of crisps set X1, X2,Xn where the n-tuple ( X1,X2,Xn) may have varying degree of membership with in the relation a. Fuzzy Relation b. Crisp Relation c. Cartesian d. Function 130. µ o (x,z) a. b. c. d. 131. µ a(x) = = yεY Max(Min (µ (x,y), µ (y,z))) yεY Min(Min (µ (x,y), µ (y,z))) yεY Max(Max (µ (x,y), µ (y,z))) yεYMin(Max (µ (x,y), µ (y,z))) 11 of 21 10/16/2011 9:31 AM NNFL file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... a. b. c. d. 132. µAα(x) = a. b. c. d. 133. ∪c = a+ µ(x) a* µ(x) µ(x) µ(x)-a (µ(x))α µ(x) α α *µ(x) a. ≠ X b. = X c. {} d. A c 134. If A={(x1,0.5), (x2, 0.7), (x3, 0)} and {(x1,0.8), (x2, 0.2), (x3, 1)} then � ∪ � is a. {(x1,0), (x2, 1), (x3, 0)} b. {(x1,0.8), (x2, 0.7), (x3, 1)} c. {(x1,0.1), (x2, 0.1), (x3, 1)} d. {(x1,1.3), (x2, 0.9), (x3,)} 135. If A={(x1,0.5), (x2, 0.7), (x3, 0)} and {(x1,0.8), (x2, 0.2), (x3, 1)} then � ∩ � is a. {(x1,0), (x2, 1), (x3, 0)} b. {(x1,0.5), (x2, 0.2), (x3, 0)} c. {(x1,0.1), (x2, 0.1), (x3, 1)} d. {(x1,1.3), (x2, 0.9), (x3,)} 136. If A={(x1,0.5), (x2, 0.7), (x3, 0)} and {(x1,0.8), (x2, 0.2), (x3, 1)} then µ � ∪ �(x2)= a. 0.1 b. 0.5 c. 0.2 d. 0 137. The product of two fuzzy set � and � whose membership function defined as µ�.� (x) a. µ�(x) . µ�(x) b. µ�(x) + µ�(x) c. µ�(x) - µ�(x) d. µ�(x) / µ�(x) 138. If �={(x1,0.2), (x2, 0.8), (x3, 0.4)} �= {(x1,0.4), (x2, 0), (x3, 0.1)} then �.� a. {(x1,0.6), (x2, 0.8), (x3, 0.5)} b. {(x1,0.08), (x2, 0), (x3, 0.04)} c. {(x1,0.01), (x2, 1), (x3, 0.03)} d. {(x1,0.02), (x2, 2), (x3, 0.01)} 139. If A={(x1,0.5), (x2, 0.7), (x3, 0)} and {(x1,0.8), (x2, 0.2), (x3, 1)} then µ � ∪ �(x1)= a. 0.8 b. 0.5 c. 1.3 d. 1 140. If A={(x1,0.5), (x2, 0.7), (x3, 0)} and {(x1,0.8), (x2, 0.2), (x3, 1)} thenµ � ∪ �(x2)= a. 0.2 b. 0.7 c. 0.1 d. 1 141. If A={(x1,0.5), (x2, 0.7), (x3, 0)} and {(x1,0.8), (x2, 0.2), (x3, 1)} thenµ � ∩ �(x1)= a. 0.1 b. 0.5 c. 0.2 d. 0 142. The union of two fuzzy sets � and � is � U � is defined with membership function µA U N (x) as a. min ( µA(x),µN(x)) b. max (µA(x),µN(x)) c. abs ( µA(x),µN(x)) d. log ( µA(x),µN(x)) 12 of 21 10/16/2011 9:31 AM NNFL file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... 143. If A={(x1,0.5), (x2, 0.7), (x3, 0)} and {(x1,0.8), (x2, 0.2), (x3, 1)} then µ � U �(x3)= a. 0 b. 0.1 c. 1 d. 3 144. The intersection of two fuzzy sets � and � is � ∩ � is defined with membership function µA ∪ N (x) as a. min ( µA(x), µN(x)) b. max ( µA(x), µN(x)) c. abs ( µA(x), µN(x)) d. log ( µA(x), µN(x)) 145. If A={(x1,0.5), (x2, 0.7), (x3, 0)} and {(x1,0.8), (x2, 0.2), (x3, 1)} then µ � U �(x3)= a. 0.1 b. 0.5 c. 0.2 d. 0 146. The complement of fuzzy set � is a new fuzzy set � with the following membership function a. µ�(x) = 1- µ�(x) b. µ�(x) = 1+ µ�(x) c. µ�(x) = 1* µ�(x) d. µ�(x) = 1/ µ�(x) 147. If �={(x1,0.5), (x2, 0.7), (x3, 0)} then �c= a. {(x1,0.5), (x2, 0.7), (x3, 0)} b. {(x1,0.5), (x2, 0.3), (x3, 1)} c. {(x1,0.3), (x2, 0.7), (x3, 0)} d. {(x1,0.5), (x2, 0.7), (x3, 3)} 148. µ�c(x1) = a. 0.5 b. 0.3 c. 1 d. 1.8 149. µ�c (x2) a. b. c. d. 150. µ�c (x3) a. b. c. d. 151. If µ�(x) a. b. c. d. = 0.5 0.3 1 1.8 = 0.5 0.3 1 1.8 =µ�(x) then the two fuzzy sets � and � are said to be Equal Product Union Intersection 152. (�∩ �)c = a. �∩ � b. �c ∩ �c c. �c∩ � d. �∩ �c 153. (� ∪ �)c = a. � ∪ � b. �c ∪ �c c. �c ∪ � d. � ∪ �c 154. �∪ �c = a. ≠ X 13 of 21 10/16/2011 9:31 AM NNFL file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... b. = X c. {} d. A c 155. If �={(x1,0.4), (x2, 0.2), (x3, 0.7)} and α=2 then (�)2= a. {(x1,0.16), (x2, 0.04), (x3, 0.49)} b. {(x1,0.4), (x2, 0.2), (x3, 0.7)} c. {(x1,0.2), (x2, 0.1), (x3, 0.1)} d. {(x1,0.1), (x2, 0.3), (x3, 0.7)} 156. If �={(x1,0.4), (x2, 0.2), (x3, 0.7)} and α=2 then µ�2(x3)= a. 0.16 b. 0.04 c. 0.49 d. 0.01 157. The disjunctive some of two fuzzy set � and � as �Θ � is a. (�c∩ �) ∪ (�∩ �c) b. (�c∩ �c) ∪ (�∩ �c) c. (�c∩ �)∪ (�c∩ �c) d. (�c∩ �) ∩ (�∩ �c) 158. µ a.�(x) a. b. c. d. = a+ µ�(x) a* µ�(x) µ�(x) µ�(x)-a 159. µAα(x) = a. (µ�(x))α b. µ�(x) c. α d. α * µ�(x) 160. Raising the fuzzy set to its second power is called a. Concentration b. Dilution c. Dilation d. Convolution 161. Taking the square root of fuzzy set is called a. Concentration b. Dilution c. Dilation d. Convolution 162. The difference �- � = a. �∩ � b. (�∪ �c) c. (�∩ �c) d. �c∩ �c 163. If �= {(x1,0.2), (x2, 0.5), (x3, 0.6)} �= {(x1,0.1), (x2, 0.04), (x3, 0.5)} then � a. {(x1,0.2), (x2, 0.5), (x3, 0.6)} b. {(x1,0.1), (x2, 0.5), (x3, 0.6)} c. {(x1,0.2), (x2, 0.5), (x3, 0.5)} d. {(x1,0.1), (x2, 0.3), (x3, 0.6)} 164. � ∪ �c = a. ≠ X b. = X c. {} d. A c 165. In the discrete case fuzzy set is defined as a. A= Σ xiεX µ (xi) /xi b. A= ΣxiεX (xi ) /xi c. A= ΣxiεX µ /xi �= 14 of 21 10/16/2011 9:31 AM NNFL file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... d. A= ΣxiεX µ (xi ) * xi 166. In the continuous case fuzzy set as a. A= xζ µ (x)/x b. A= xζ (x)/x c. A= xζ µ (x)+x d. A= xζ µ(x)*x 167. The following is associated with fuzzy set A such that the function maps every elements of the universe of discourse X to the interval [0,1] a. Threshold function b. Membership function c. Sigmoid function d. Hyperbolic 168. Mathematically membership function is a. µ=1/(1+x)2 b. µ=(1+x)2 c. µ= x2 d. µ=1+x 169. If � ={(x1,0.2), (x2 0.8)} �= {(x1,0.6), (x2, 0.8)}, �= {(x1,0.2), (x2, 0.8)} then a. �= � b. �` � c. �= � d. �= 3� 170. If � ={(x1,0.2), (x2 0.8)} �= {(x1,0.6), (x2, 0.8)}, �= {(x1,0.2), (x2, 0.8)} then a. �= � b. �≠ � c. �= � d. �= 3� 171. The following sets support a flexible sends of membership of elements to a set a. Fuzzy set b. Logic set c. Certain set d. Crisp set 172. In the following set theory an element either belong to or doesn t belong to a set a. Fuzzy set b. Logic set c. Certain set d. Crisp set 173. In the following set theory many degrees of membership are allowed a. Fuzzy set b. Logic set c. Certain set d. Crisp set 174. The following function values need not always be described by discrete values a. Membership b. Index c. Position d. Class 175. If � ={(x1,0.2), (x2, 0.8)} �= {(x1,0.6), (x2, 0.8)}, �= {(x1,0.2), (x2, 0.8)} then a. �= � b. �≠ � c. �= � d. �= 3� 176. The following logic had its roots in the theory of crisp sets a. Fuzzy logic b. Boolean logic c. Prolog d. ELIZA 177. Uncertainty arises due to following a. Complete information 15 of 21 10/16/2011 9:31 AM NNFL file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... b. Partial information c. Clear information d. Coherent information 178. The statements of (0 /1) type of handling is termed as the following the domain of fuzzy set theory a. Crisp b. Lisp c. Prolog d. ELIZA 179. Crisp logic is of a. Single valued b. Multivalued c. Ambiguious valued d. Non defined valued 180. Fuzzy logic is of a. Single valued b. Multivalued c. Ambiguious valued d. Non defined valued 181. The following logic is of two values a. Crisp logic b. Fuzzy logic c. Bayes logic d. Probability theory 182. In the following logic truth values are multi valued a. Crisp logic b. Fuzzy logic c. Predicate logic d. Prepositional logic 183. The following theory is an excellent mathematical tool to handle the uncertainty arising due to vagueness a. Fuzzy set theory b. Crisp logic c. Classical set theory d. Prepositional logic 184. The following may arise due to partial information about the problem a. Clarity b. Uncertainty c. Perfection d. Unambiguity 185. Classical a. b. c. d. set theory also termed as Crisp Lisp Prolog ELIZA 186. Number of pictures that can be stored at a time is a. Only one b. Two c. Any number of pictures d. It depends on training 187. If bipolar patterns are used a. P=n/(log2n) b. P=n/(log2n) c. P=2n/(2log2n) d. P=3n/(2log2n) 188. The Hopfield network consists of a set of neurons forming a multiple loop of following system. a. Unidirectional b. Parallel c. Feedback d. Feed forward 189. The magnetic mutual exchange between the alones led to the development of a. Simulated annealing b. McCulloh piths c. Hopfield 16 of 21 10/16/2011 9:31 AM NNFL file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... d. Boltzmann's Machine 190. The following network is able to recognize unclear pictures correctly a. Simulated annealing b. McCulloh Pitts c. Hopfield d. Boltzmann's Machine 191. In Hopfield net a. Only one unit updates its activation at a time b. Many units c. Does not update at all d. Activation function is not present 192. In Hopfield net the number of binary patterns that can be stored and recalled in a net with reasonable accuracy a given by a. P ≈ 0.15n b. P ≈ 0.25n c. P ≈ 0.35n d. P ≈ 0.5n 193. The following sets have a tendency to stabilize to a local minima rather than global minima a. Hopfield b. BAM c. Boltzmann's machine d. ART1 194. In the following network an individual units doesn t connect to itself a. Hopfield b. BAM c. Boltzmann's machine d. ART1 195. Simulated annealing, Boltzmann s Machine, Hopfield nets belongs to a. Feed forward b. Feedback c. Feed follow d. Adhoc 196. The asynchronous discrete time updating of the units allows a function known as [b] a. Time function b. Energy function c. Memory for d. Signal function 197. Energy function is also called as the following function to be found for net a. Boltzmann s Machine b. Lyapnuov function c. Sigmoid function d. Threshold function 198. The following functions proves that the net will converge to a stable set of actuations a. Boltzmann's Machine b. Lyapnuov function c. Sigmoid function d. Threshold function 199. Hop field network is a. Feed forward b. Feed back c. Feed follow d. Adhoc 200. In the following mode of training, all neurons in Hopfield networks fire at the same time. a. Stable state b. Output c. Synchronous d. Asynchronous 201. If |A| = n then |P (A)|= a. 2n b. 2n c. n 2 d. n + n 17 of 21 10/16/2011 9:31 AM NNFL file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... 202. The value of |A| in singleton set A is a. 1 b. 0 c. 5 d. Depends on the number of elements in A 203. X= {1,2,3,4,5,6,7} and A= {5, 4,3} then Ac= a. {1,2,6,7} b. {1,2,3,4} c. {6,7} d. {5} 204. If A={a,b,c,1,2} B={1,2,3,a,c} then A ∩ B= a. {a,c,1,2} b. {a,b,c} c. {a,c} d. {} 205. Given A={a,b,c,1,2} B={1,2,3,a,c} then A ∪ B= a. {a,b.c,1,2,3} b. {a,b,c} c. {1,2,3} d. {} 206. The complement of set A is denoted by a. b. A c c. and Ac d. A 207. If A ∩ B=φ then the two sets are a. Joint b. Disjoint c. Subsets d. Supersets 208. If A= {a,b,c,d,e} B={b,d} then A-B= a. {a,c,e} b. {a,c} c. {a} d. {d} 209. If |A| = 4 then |P (A)|= a. 16 b. 4 c. 10 d. 8 210. A ∩ Ac = a. b. c. d. φ is Commutative Associative Distributive Law of contradiction 211. According to Demorgan's laws (A∪B)c = a. A c ∪ B c b. A ∪ B c c. A c∪ B d. Ac ∩ Bc 212. According to Demorgan's laws (A∩B)c= a. Ac ∪ B c b. A ∪ B c c. A c∪ B d. A c∩ B c 213. Partition on A indicated as π (A) is therefore for each pair (i,j)εI for i≠j a. Ai ∩ Aj = θ b. iεJ ∩ A i =A 18 of 21 10/16/2011 9:31 AM NNFL file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... c. iεJ ∩ A i =1 d. iεJ ∩ A i =0 214. The following on A is defined to a set of non empty subsets Ai , whose union yields the original set A a. Partition b. Covering c. Opening d. Closing 215. The following on A is defined to a set of non empty subsets Ai , each of which is pair wise disjoint and whose union yields the original set A a. Partition b. Covering c. Opening d. Closing 216. |A| = |∪ i=1..n Ai|=Σ i=1..n|Ai| is a. Rule of addition b. Rule of inclusion c. Rule of exclusion d. Rule of application 217. If the subsets are not pair wise disjoint then the following is not applicable on the covering of set A a. Rule of addition b. Rule of inclusion c. Rule of exclusion d. Rule of application 218. A ∪ B= B a. b. c. d. 219. A∪ A = A a. b. c. d. ∪ A is the following property of set Commutative Associative Distributive Idempotence is the following property of set Commutative Associative Distributive Idempotence 220. A ∩ (B ∪ C) = (A ∩ B) ∪ (A ∩ C) is the following property of set a. Commutative b. Associative c. Distributive d. Idempotence 221. A ∩ E = A is the following property of set a. Commutative b. Associative c. Distributive d. Identity 222. A ∪ (A∩ B) = A is the following property of set a. Commutative b. Associative c. Distributive d. Law of absorption 223. If A ≤ B, a. b. c. d. B≤ C then A ≤ C is Commutative Associative Distributive Transitive 224. (Ac)c=A is the following property a. Commutative b. Associative c. Distributive d. Involution 225. A ∪ Ac = E is a. Commutative b. Associative 19 of 21 10/16/2011 9:31 AM NNFL file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... c. Distributive d. Law of excluded middle 226. In discrete BAM for Binary input vectors, the weight matrix can be determined by the formula a. W ij=Σ p (2Si(p)-1) (2t j(p)-1) b. W ij=Σ p (2S i(p)+1) (2t j(p)-1) c. W ij=Σ p (2S i(p)-1) (2t j(p)+1) d. W ij=Σ p (2S i(p)+1) (2t j(p)+1) 227. In discrete BAM for Bipolar input vectors, the weight matrix can be determined by the formula a. W ij=Σ p Si(p) 2t j(p) b. W ij=Σ p (2S i(p)+1) (2t j(p)-1) c. W ij=Σ p (2S i(p)-1) (2t j(p)+1) d. W ij=Σ p (2S i(p)+1) (2t j(p)+1) 228. In continuous BAM for binary input vectors the weights are determined by the formulae a. W ij=Σ p (2Si(p)-1) (2t j(p)-1) b. W ij=Σ p (2S i(p)+1) (2t j(p)-1) c. W ij=Σ p (2S i(p)-1) (2t j(p)+1) d. W ij=Σ p (2S i(p)+1) (2t j(p)+1) 229. Logistic sigmoid activation function in Y layer is given by a. f(yin j)=1/(1+exp(-yin j) b. f(yin j)=1+(1+exp(-yin j) c. f(yin j)=1-(1+exp(-yin j) d. f(yin j)=1*(1+exp(-yin j) 230. If the net input is equal to the threshold value, the activation function decide to a. Leaves the activation of that unit to higher value b. Leaves the activation of that unit to previous value c. Zero d. One 231. The following memory has the capability to transfer the input smoothly and continuously into respective output in the range between [0,1] a. Continuous BAM b. Discrete BAM c. Hetero associative memory d. Auto associative memory 232. The continuous BAM uses the following function as the activation function a. Step activation with Zero threshold b. Step activation with non-zero threshold c. Logistic sigmoid function d. Hyperbolic tangent function 233. If bias is a. b. c. d. included in calculating the net input in Y layer then f(yin j ) f(yin j) =bj+ΣxiWij f(yin j) =b j-ΣxiW ij f(yin j) = ΣxiW ij f(yin j) =b j+ΣWij 234. Bidirectional associative memory is developed by a. Rumelhart b. Wilson c. Hecht d. Kosko 235. BAM is a. b. c. d. 236. Different a. b. c. d. Auto Associative recurrent network Hetero Associative recurrent network Hop field network Perceptron forms of BAM are Only binary Only Bipolar Only continuous Binary, Bipolar, continuous 237. The activation function used in discrete BAM is a. Step activation with Zero threshold b. Step activation with non-zero threshold 20 of 21 10/16/2011 9:31 AM NNFL file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... c. Logistic sigmoid function d. Hyperbolic tangent function. 238. The continuous BAM was introduced by a. Rumelhart b. Neilson c. McCulloh d. Kosko 239. The difference between the number of bits in two binary or bipolar vectors x1 and x2 is called a. Hamming distance b. Euclidean distance c. Mean distance d. Variance 240. The average hamming distance between the vectors is a. 1/n [HD(x1,x2)] b. 1/2n [HD(x1,x2)] c. 1/3n [HD(x1,x2)] d. 1/2 [HD(x1,x2)] 21 of 21 10/16/2011 9:31 AM PED file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... JNTU ONLINE EXAMINATIONS [Mid 2 - PED] 1. Stator voltage Vs is proportional to a. stator flux/ frequency b. stator flux * frequency c. stator flux + frequency d. stator flux - frequency 2. In cranes and Lifts ______ type of motor is used a. Cage motor b. wound motor c. special motor d. generator 3. Speed torque characteristics of a slip ring motor are a. exponential raise b. exponential decay c. rectangular hyperbola d. rectangular parabola 4. Synchronous speed of an induction motor inversely proportional to a. Rotor speed b. Number of poles c. Frequency d. Stator speed 5. Range of a. b. c. d. slip of an induction motor from stand still to synchronous speed 0 to 1 1 to 0 1 to -1 0 to -1 6. For an induction motor s is slip, fs is the stator frequency then rotor frequency fr is equal to a. fs /s b. fs * s c. fs + s d. fs - s 7. In equivalent circuit of an induction motor, if Rr is the rotor value, n is the stator to rotor turns ratio then the stator referred value is equal to a. Rr / n b. Rr / n 2 c. Rr + n d. Rr * n2 8. In an induction motor for a fan load, s is the slip and K is the torque constant then load torque TL is equal to a. K (1/s2) b. K (1-s2) c. K (1-s)2 d. K +(1-s2) 9. Find out a. b. c. d. the speed of induction motor, whose slip is 0.4 and synchronous speed is 1000rpm 500 rpm 2000 rpm 1000rpm 600 rpm 10. In equivalent circuit of an induction motor, if Rs is the stator value, n is the stator to rotor turns ratio then the rotor referred value is equal to a. Rs / n b. Rs / n2 c. Rs + n d. Rs * n2 11. The slip is less than zero in a. Motoring region b. Generating region 1 of 18 10/16/2011 9:32 AM PED file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... c. Braking region d. Regenerating region 12. The maximum torque is independent of a. Stating resistance b. Maximum resistance c. Rotor resistance d. Voltage 13. Maximum slip is directly proportional to a. Stator resistance b. Rotor resistance c. Maximum resistance d. Voltage 14. When the rotor in stationary, the torque corresponds to the starting torque when a. Slip is equal to unity b. Slip is less than unity c. Slip is greater than unity d. Slip is equal to zero 15. Which of a. b. c. d. the following motor preferred for high starting torque application Squirrel cage induction motor Slip ring induction motor Synchronous motor DC Shunt motor 16. Synchronous speed is directly proportional to a. Rotor speed b. Number of poles c. Frequency d. Stator speed 17. When torque is equal to zero a. Slip is equal to zero b. Slip is equal to unity c. Slip is less than unity d. Slip is greater than unity 18. The torque has a maximum value, called a. Break over torque at slip minimum b. Break down torque at slip minimum c. Break down torque at slip maximum d. Break over torque at slip maximum 19. The torque is positive but the speed is negative, so ___________ torque appears as breaking torque a. Costing b. Braking c. Motor d. Plugging 20. The slip is greater than unity a. Motoring region b. Braking region c. Regenerating region d. Generating region 21. What is the disadvantage of an induction motor using stator voltage controller a. The control circuit is very simple b. The input power factor is very low c. More compact and less weight d. Its response time is quick 22. Slip speed is proportional to a. Voltage b. Current c. Frequency d. Slip 23. Speed control of AC drives can not be achieved by varying a. Voltage b. Current c. Frequency d. Efficiency 2 of 18 10/16/2011 9:32 AM PED file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... 24. Different a. b. c. d. between synchronous speed and actual speed called as Rotor speed Slip Frequency Slip speed 25. Torque is proportional to a. Voltage b. Square of its voltage c. Frequency d. Current 26. Varying the stator voltage can control the induction motor speed as a. Above the rated speed b. Below the rated speed c. Above and below the rated speed d. Below the slip speed 27. Stator voltage control for speed control of induction motors is suitable for a. drive of a crane b. constant load drive c. running if as generator d. fan and pump drives 28. By using a. b. c. d. 29. By using a. b. c. d. AC voltage controller, ___________ can be fixed supply voltage current supply frequency Flux AC voltage controller, ___________ can be fixed Supply voltage Current Slip Efficiency 30. What is the advantage of an induction motor using stator voltage controller a. Performance is poor b. Operating frequency is low c. Maximum torque available from the motor d. There is a consideration saving in energy 31. How to measure the speed of an induction motor in closed loop system a. Brushes b. Wattmeter c. Tacho-generator d. Multimeter 32. What is meant by electric drive a. Drive employing engines b. Driven by turbine c. Drive employing electric motors d. Drive by steam 33. In closed loop speed control of an induction motor using stator voltage, a. Varying phase control b. Varying frequency c. Varying negative gate current d. Varying negative gate voltage 34. What is the disadvantages of squirrel cage induction motor a. Starting torque b. High efficiency c. Cheaper d. Speed 35. The rotor moves in the same direction as that of the rotating magnetic field to reduced the induced current according to a. Motion law b. Lenz s law c. Faraday s law d. Right hand rule 36. Difference between reference speed and actual speed called as a. Maximum speed 3 of 18 10/16/2011 9:32 AM PED file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... b. Rotor speed c. Error speed d. Stator speed 37. With poles = 6, speed is 1000 rpm then with poles = 8, speed is a. 1250 rpm b. 1500 rpm c. 3000 rpm d. 750 rpm 38. When the motor speed is equal to the reference speed a. Motor torque is equal to the load torque b. Shaft torque is equal to the load torque c. Maximum torque is equal to shaft torque d. Stating torque is equal to shaft torque 39. Which device is suitable for fan control application a. Power transistor b. Power Diode c. Triac d. Zener diode 40. What is meant by stator voltage control of squirrel cage Induction motor a. Rotor resistance control b. Slip power recovery control c. Stator voltage & supply frequency control d. Direct torque control 41. Current a. b. c. d. limit control scheme is employed to limit the converter and motor current Above the safe limit during transient operation Below the safe limit during transient operation Both Above the safe limit during transient operation and Below the safe limit during transient operation It can not allow the current 42. When the starting torque can be increased steplessly from its zero value. Such a start is known as __________ a. Hard start b. Soft start c. Medium start d. Both Hard start and Soft start 43. If the rotor speed becomes greater than synchronous speed, relative a. Speed between the rotor conductor and air gap rotating field reverse b. Speed between the rotor conductor and air gap rotating field forward c. Both Speed between the rotor conductor and air gap rotating field reverse and Speed between the rotor conductor and air gap rotating field forward d. Speed between the rotor conductor and air gap rotating field same 44. During electric braking motor current tends to a. Exceed the safe limit b. Below the safe limit c. Both Exceed the safe limit and Below the safe limit d. No current to the motor 45. Acceleration and deceleration modes are a. Steady-state operation b. Transient operation c. Stand still operation d. Motoring operation 46. Drive operates in ____________mode whenever an increase in its speed is required a. Acceleration b. Deceleration c. Braking d. Power 47. Closed loop drives require a. Slow response b. Medium response c. Fast response d. No response 48. A special case of plugging occurs when an induction motor connected to positive sequence voltage is driven by an active load in the reversing direction a. Quadrant IV 4 of 18 10/16/2011 9:32 AM PED file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... b. Quadrant III c. Quadrant II d. Quadrant I 49. Drive operates in ____________ depending on the direction of rotation a. Quadrant I or III b. Quadrant III or IV c. Quadrant III or II d. Quadrant II or IV 50. When load torque opposes motion, then it works as a motor operating in ___________ depending on the direction of rotation a. Quadrant I or III b. Quadrant I or IV c. Quadrant I or II d. Quadrant II or III 51. At low frequency where ( V/f ) ratio is increased to keep a. Minimum torque constant b. Nominal Torque c. Maximum torque constant d. Fixed torque 52. Frequency control of an induction motor drives employ a. AC voltage controller b. Semi-converter c. Cycloconverter d. Chopper converter 53. Variable frequency control of an induction motor, terminal voltage can be considered proportional to the product of a. Frequency and flux b. Frequency and voltage c. Flux and voltage d. Voltage and torque 54. Variable a. b. c. d. frequency control of an induction motor, drop in speed from no load to full load is High Medium Small Both High & Medium 55. Speed control of three phase induction motor, synchronous speed is directly proportional to the a. No. of poles b. Supply frequency c. Resistance d. Current 56. Any reduction in the supply frequency, without a change in the terminal voltage, causes an a. Decrease in the air gap flux b. Decrease in the rotor frequency c. Increase in the air gap flux d. Increase in the rotor frequency 57. In motoring operation, ( V/f ) ratio is increased at a. High frequency b. High flux c. Low frequency d. Low flux 58. Variable frequency control of an induction motor, speed control and braking operation are available from nearly zero speed to a. Above the asynchronous speed b. Above the synchronous speed c. Below the asynchronous speed d. Below the synchronous speed 59. The breakdown torque is a function of slip at a. Low frequency b. High frequency c. Medium frequency d. Constant frequency 60. In Three phase induction motor air gap flux of the machine is kept constant, like a a. DC series motor 5 of 18 10/16/2011 9:32 AM PED file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... b. DC shunt motor c. DC compound motor d. Both DC series motor & DC shunt motor 61. Generally MOSFET is used in a. Low voltage and low power inverter b. High voltage and low power inverter c. High voltage and high power inverter d. Low voltage and high power inverter 62. The voltage source inverter has a. High internal impedance b. High internal Resistance c. Low internal Reactance d. Low internal impedance 63. The voltage source inverter allows a variable frequency supply to be obtained from a a. AC supply b. DC supply c. Both AC supply & DC supply d. Impedance source 64. Speed control schemes are available for control of induction motor on a. Stator side b. Rotor side c. Both Stator side & Rotor side d. Shaft side 65. What is meant by VSI a. Source contains negligible impedance b. Source contain more impedance c. It is a variable voltage source d. Both Source contain more impedance & It is a variable voltage source 66. In general, Frequency of rotor currents = Frequency of supply voltage when a. Slip = 0 b. Slip = 0.5 c. Slip = 1 d. Slip = -1 67. By using a. b. c. d. voltage source inverters along with controlled rectifier, _______ is possible Motoring Braking Either Motoring or Braking Regenerating 68. The drawback of stepped wave inverter is a. Harmonics are eliminated at low frequency b. Large harmonics at low frequency c. Harmonic content in the motor current decrease at low speed d. Both Harmonics are eliminated at low frequency & Harmonic content in the motor current decrease at low speed 69. Presence of low frequency harmonics, a. More losses at all speed b. Less losses at all speed c. No losses at all speed d. Both More losses at all speed & Less losses at all speed 70. The harmonics in the motor current produce a. Torque pulsation b. Torque harmonic c. No torque d. Both Torque pulsation & Torque harmonic 71. _______________ is produced by air gap flux at one frequency interacting with rotor mmf at a different frequency a. Harmonic heating b. Air gap current c. Harmonic ripple d. Torque pulsation 72. In a current-fed inverter drive, the two control variable are a. DC link current and frequency b. Frequency and slip 6 of 18 10/16/2011 9:32 AM PED file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... c. DC link current and slip d. DC link current and voltage 73. Variable a. b. c. d. stator current control operation, the developed torque depends on the relative distribution of Rotor current and stator current Stator current and magnetizing current Rotor current and magnetizing current Both Stator current and magnetizing current & Rotor current and magnetizing current 74. The developed torque of the drive can be controlled either by a. DC link current or Frequency b. DC link current or Slip c. DC link current or voltage d. Frequency or slip 75. The major advantage of CSI is a. More in reliability b. Poor in reliability c. Slower dynamic response d. Faster dynamic response 76. Change of phase sequence of CSI will provide motoring and braking operations in the a. Forward direction b. Reverse direction c. Both Forward direction & Reverse direction d. Standstill 77. In minimal close loop control system of a CSI, the dc link current and slip are a. Controlled independently b. Controlled dependently c. Both ( a & b ) d. Proportional 78. In acceleration mode, the slip is a. Positive b. Negative c. Zero d. Infinity 79. In voltage / frequency control, maximum torque obtained is ________ with change in slip a. Fixed b. Variable c. Both Fixed & Variable d. Zero 80. When the frequency is reduced, the input voltage must be reduced proportionally is called as a. Voltage control b. Frequency control c. Current control d. V/f control 81. The advantage of PWM control inverter-fed induction motor drives is a. Low switching losses b. Simple control circuit c. Less harmonic content d. Both Low switching losses & Simple control circuit 82. The PWM techniques, gain is inversely proportional to a. Peak voltage of the fundamental b. Peak current of the fundamental c. Peak value of the modulating wave d. Peak value of the carrier wave 83. The PWM techniques, gain is directly proportional to a. Fundamental peak voltage b. Fundamental peak current c. Fundamental harmonics d. Both Fundamental peak voltage & Fundamental peak current 84. Using PWM techniques -----------can be controlied a. Only voltage b. Only frequency c. Only Current d. Voltage, frequency and current 7 of 18 10/16/2011 9:32 AM PED file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... 85. The ratio of peak value of the modulating wave and peak value of the carrier wave is defined as a. Modulating frequency b. Modulating index c. Modulating wave d. Modulating carrier 86. Modulating index can be varied between a. Infinity to zero b. Finite to infinity c. Zero to unity d. Unity to infinity 87. An important effect of PWM switching frequency is the generation of a. Magnetic noise b. Voltage noise c. Frequency noise d. No noise 88. The disadvantage of PWM techniques is a. More switching losses b. Low efficiency c. High current distortion d. Torque more 89. What is mean by SHE-PWM a. Small harmonic elimination PWM b. Single harmonic elimination PWM c. Selective harmonic elimination PWM d. Signal harmonic elimination PWM 90. The PWM techniques reduce the a. Harmonic heating and torque pulsation b. Torque pulsation and magnetic noise c. Acoustic noise, Harmonic heating and torque pulsation d. Switching losses and efficiency 91. The closed loop speed control drive uses a PWM inverter fed from a dc source, which has capability for a. Only two-quadrant operation b. One-quadrant operation c. Only three-quadrant operation d. All four-quadrant operation 92. The ratio of peak output phase voltage and maximum possible peak phase voltage is known as a. Modulation index b. Modulation wave c. Modulation factor d. Modulation carrier 93. Cycloconverter drive has applications in high power drives requiring good dynamic response but only a. High speed operation b. Standstill operation c. Costing speed operation d. Low speed operation 94. The cycloconverter induction motor drives has fast response because the speed error is corrected at a. The maximum available torque b. The minimum available torque c. Zero torque d. Both The maximum available torque & The minimum available torque 95. Cycloconverter allows ___________supply to be obtained from a fixed voltage and frequency ac supply a. Fixed frequency and fixed voltage b. Fixed frequency and variable voltage c. Variable frequency and fixed voltage d. Variable frequency and variable voltage 96. A motor a. b. c. d. with large leakage inductance is used in order to minimize Derating and torque pulsations Voltage regulation Switching losses Magnetic noise 97. The PI-controller is used to get a. Poor responses 8 of 18 10/16/2011 9:32 AM PED file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... b. Poor steady-state accuracy c. Good steady-state accuracy d. Good delay time response 98. The slip-speed command is set at the maximum negative value, the drive decelerates under a. Motoring b. Generative braking c. Regenerative braking d. Plugging 99. The output frequency may vary from zero to an upper limit, which is always lower than the input frequency is called as a. Step-up cycloconverter b. Step-down cycloconverter c. Step-up and Step-down cycloconverter d. Chopper 100. The step-down cycloconverter thyristors turn-OFF by using a. Line commutation b. Forced commutation c. Load commutation d. Self commutation 101. Compared to conventional rotor resistance control, static rotor resistance control has several advantage because of a. Smooth and stepless control b. Maintenance is more c. Low response d. Both Maintenance is more & Low response 102. In motor circuit static frequency changers are used for a. Power factor improvement b. Improved cooling c. Reversal of direction d. Speed regulation 103. Rotor resistance speed control is used in a. Squirrel cage Induction motor b. Synchronous Motor c. Slip ring Induction Motor d. DC shunt Motor 104. The motor normally used for crane travel is a. Ward Leonard controlled DC shunt motor b. Synchronous c. DC differentially compound motor d. AC slipring motor 105. In rotor resistance control of induction motor, the hardness of speed torque characteristics a. Increases b. Decrease c. Increases and decreases d. Remain same 106. The major disadvantage of rotor resistance control is a. High torque b. High efficiency c. Low torque d. Low efficiency 107. Maximum Torque of an induction motor occurs at slip (S) is equal to a. Zero b. Infinity c. Unity d. Rotor resistance/ Rotor reactance 108. Rotor resistance control is employed in----a. DC shunt motor drives b. DC series c. Ward Leonard drives d. Both DC shunt motor drives & DC series 109. In using rotor resistance control a. Starting torque is less b. Zero starting torque 9 of 18 10/16/2011 9:32 AM PED file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... c. Starting torque is high d. Both Starting torque is less & Zero starting torque 110. Belted wound rotor induction motor are preferred for a. machine tools b. gyratory crushers c. belt converter d. water pumps 111. Slip power recovery scheme air gap power is directly proportional to a. Mechanical output power b. Slip c. Both Mechanical output power & Slip d. Zero torque power 112. In Slip Power recovery scheme what is the formula for Pm in terms of slip and Pg a. Pm =(1-S)Pg b. Pm =SPg c. Pg =(1-S)Pm d. Pg =S Pm 113. Speed control ____________is obtained by controlling the slip-power.Above the synchronous speed a. Above the synchronous speed b. Below the synchronous speed c. At zero speed d. Both Above the synchronous speed & Below the synchronous speed 114. Pole changing method of speed control is used in a. Slip-ring induction motor b. Dc shunt motor c. Dc series motor d. Squirrel cage induction motor 115. An induction motor operation with an injected voltage in its rotor a. Stator voltage control b. Rotor resistance control c. Slip power control d. Variable frequency control 116. Slip power recovery scheme is only suitable for a. DC shunt motor b. Slip-ring induction motor c. Synchronous motor d. Both Slip-ring induction motor & Synchronous motor 117. The principles of slip-power control is particularly popular in a. Ward Leonard Ilgener drives b. Static Kramer drives c. Static scherbius drives d. Both Static Kramer drives & Static scherbius drives 118. The static Kramer drive cannot have a. Motor braking capability b. Regenerative braking capability c. Both Motor braking capability & Regenerative braking capability d. Motoring capability 119. Slip power recovery system has nearly the characteristics of a. DC shunt motor b. DC series motor c. Self excited dc motor d. Separately excited dc motor 120. Following is the ratio of air gap power Pg : rotor copper loss Pcu : mechanical power Pm a. 1: (1-s): s b. 1: s : (1-s) c. Pg =(1-S)Pm d. Pg =S Pm 121. Identify the current Id equation of Scherbius Drive system from the following a. b. c. d. 10 of 18 10/16/2011 9:32 AM PED file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... 122. For safe commutation slip S=________ a. (m/n) cosα b. -(m/n) cosα c. -(n/m) cosα d. (m/n) sinα 123. In Slip power recovery the amount of power to be injected in rotor is _______ a. (1-S)Pg b. S Pg c. (1-S)Pm d. S Pm 124. Maximum .firing angle restricted for safe commutation of thyristors in Scherbius drive is a. 150 b. 165 c. 180 d. 0 125. Slip power recovery scheme among the following is________ a. static rotor resistance control b. static Kramer s drive c. Four quadrant control d. Regenerative control 126. Expression for Rectifier output in Static Scherbius drive is ____________ a. b. c. d. 127. Expression for Inverter input in Static Scherbius drive is ____________ a. b. c. d. 128. In Scherbius Drive system in Vd1 equation n is called ____________ a. Stator to rotor turns ration of motor b. turns ratio of transformer c. Turns ratio of converter d. Slip of the motor 129. Following is the very low power factor drive a. static rotor resistance control b. static Scherbius Drive c. Four quadrant control d. Regenerative control 130. Expression for Rectifier output in Static Scherbius drive is ____________ a. b. c. d. 131. Expression for Inverter input in Static Scherbius drive is ____________ a. b. c. d. 132. In Scherbius Drive system in Vd1 equation n is called ____________ a. Stator to rotor turns ration of motor b. turns ratio of transformer c. Turns ratio of converter d. Slip of the motor 133. Following is the very low power factor drive a. static rotor resistance control b. static Scherbius Drive c. Four quadrant control d. Regenerative control 134. The selection of control gear for a particular application is based on the consideration of a. duty 11 of 18 10/16/2011 9:32 AM PED file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... b. starting torque c. limitations on starting current d. duty, starting torque & limitations on starting current 135. Pole changing method of speed control is used in a. Slipring induction motor b. Dc shunt motor c. Dc series motor d. squirrel cage induction motor 136. Which of a. b. c. d. the following is preferred for automatic drives synchronous motors ward Leonard controlled dc motor squirrel cage induction motor - 137. Belted wound rotor induction motor are preferred for a. machine tools b. gyratory crushers c. belt converter d. water pumps 138. Belted wound rotor induction motor are preferred for a. machine tools b. gyratory crushers c. belt converter d. water pumps 139. The motor normally used for crane travel is a. AC slipring motor b. Ward Leonard controlled DC shunt motor c. Synchronous d. DC differentially compound motor 140. A wound rotor induction motor is preferred over squirrel cage induction motor when the major consideration involved is a. high starting torque b. low starting current c. speed control over limited range d. high starting torque,low starting current,speed control over limited range 141. Stator voltage control for speed control of induction motors is suitable for a. fan and pump drives b. drive of a crane c. running if as generator d. constant load drive 142. As compared to squirrel cage induction motor a wound motor induction motor is preferred when the major consideration is a. High starting torque b. low winding losses c. slow speed operation d. High starting torque, low winding losses & slow speed operation 143. In motor circuit static frequency changers are used for a. power factor improvement b. improved cooling c. Reversal of direction d. speed regulation 144. To save the energy during braking a. Dynamic braking is used b. Plugging is used c. Regenerative braking is used d. mechanical braking is used 145. In jaw crushers, a motor has to often started against a. low load b. medium load c. normal load d. heavy load 146. Centrifugal pumps are usually drive by a. d.c. shunt motor b. d.c. series motor 12 of 18 10/16/2011 9:32 AM PED file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... c. squirrel cage I.M. d. 147. Most commonly used AC motor is a. Synchronous motor b. slip ring induction motor c. squirrel cage induction motor d. AC commutator induction motor 148. Belted slip ring I.M. is almost invariably used for a. centrifugal blowers b. jaw crushers c. water pump d. screw pumps 149. The motor commonly used in computers and digital systems is a. DC shunt motor b. Induction motor c. Stepper motor d. Synchronous motor 150. Which of a. b. c. d. the following drive can be used for derricks and winches? DC motors with Ward Leonard control AC slip-ring motors Pole changing slipring motors DC Seperately excited motors 151. A pole changing type squirrel cage motor used in derricks has four, eight and twenty, fourPoles. In this the lowest speed is used for a. lifting b. hoisting c. lowering d. landing the load 152. Which of a. b. c. d. 153. Which of a. b. c. d. 154. Which of a. b. c. d. the following motor is preferred for blowers wound rotor I.M Squirrel cage induction motor d.c. shunt motor d.c. series motor the following motor is preferred for synthetic fiber mills? series motor reluctance motor shunt motor synchronous motor the following motor is preferred for synthetic fiber mills? series motor reluctance motor shunt motor synchronous motor 155. The advantage of a synchronous motor in addition to its constant speed is a. high power factor b. better efficiency c. lower cost d. high power factor, better efficiency & lower cost 156. Damper winding not used for___________ a. speed control b. damping of oscillations c. starting of synchronous motor d. high power factor 157. Most Synchronous motors are rated between a. 150 KW to 15MW b. 15MW to 150MW c. 15 KW to 150 KW d. 1 KW to 2 KW 158. In Salient Pole motor '&delta' is the angle between a. V and Is b. V and E c. E and Isd d. Isd and Isq 13 of 18 10/16/2011 9:32 AM PED file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... 159. In Cylindrical rotor wound motor for Motoring operation a. δ is Positive b. E lags V c. δ is Positive and E lags V d. δ is Positive or E lags V 160. A synchronous motor is found to be more economical when the load is above a. 1 kW b. 10 kW c. 20 kW d. 100 kW 161. Expression for Salient pole rotor synchronous motor consists of ___ no. of parts a. 1 b. 2 c. 3 d. 4 162. The time a. b. c. d. 163. The time a. b. c. d. period of Reluctance torque component is_____ times of Synchronous torque 1 2 3 4 period of Reluctance torque component is_____ times of Synchronous torque 1 2 3 4 164. In Cylindrical rotor wound field motor load angle � is ____ for maximum torque a. 0 b. 90 c. 180 d. 165 165. In Cylindrical rotor wound field motor load angle � is ____ for maximum torque a. 0 b. 90 c. 180 d. 165 166. One of the following power circuits is used for synchronous motor speed control through Frequency identify a. V.S.I b. A.C Voltage controller c. 3 φ controlled converter d. 167. Multi motor control system is possible from a. open loop b. closed loop c. open or closed loop d. 168. Identify Self Control from the following a. Closed loop control b. open loop control c. either closed or open loop d. 169. Following is the scalar control mode of control in an synchronous motor a. open loop b. closed loop c. open or closed loop d. 170. Identify variable frequency control mode from the following a. separate control b. self control c. either a or d. 171. Multi motor control system is possible from 14 of 18 10/16/2011 9:32 AM PED file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... a. b. c. d. 172. Variable a. b. c. d. true synchronous mode closed loop mode open or closed loop frequency control is possible in Synchronous motor below base frequency above base frequency at base frequency at any frequency 173. In Cylindrical rotor wound field motor for lagging power factor a. V leads Is b. V lags Is c. E lags V d. V lags E 174. In Salient pole wound field motor , reluctance torque is proportional to____ a. Sin δ b. Sin 2δ c. Sin δ/2 d. sin&phi 175. In Cylindrical rotor wound field motor for lagging power factor a. V leads Is b. V lags Is c. E lags V d. V lags E 176. In Salient pole wound field motor , reluctance torque is proportional to____ a. Sin δ b. Sin 2δ c. Sin δ/2 d. sin&phi 177. Frequency = 50 Hz, Poles = 4, Synchronous Speed for 3 - phase induction motor is a. 1500 rpm b. 1000 rpm c. 2000 rpm d. 1200 rpm 178. CSI fed Synchronous motor is suitable fora. multi drive b. unsuitable for multi drive c. suitable for both a & b d. 179. Identify the Constant Power Region a. zero to base speed b. Above base speed c. slip speed d. 180. In True Synchronous mode Frequency is controlled from a. Encoder b. Oscillator c. Inverter d. 181. PWM technique in Inverters for control of Synchronous motor is used for a. harmonic reduction b. higher output frequency c. improving efficiency d. reducing switching losses 182. The variable frequency supply to an induction motor for speed control can be made available using a. VSI b. CSI c. cycle converter d. VSI, CSI & Cycle converter 183. What is meant by VSI ? a. source contain negligible impedance b. source contain more impedance c. It is a variable voltage source 15 of 18 10/16/2011 9:32 AM PED file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... d. source impedance is zero 184. What is meant by CSI ? a. source contain large impedance b. source contain loss impedance c. constant voltage source d. source impedance is zero 185. In variable frequency control of synchronous motor drive the machine settles at new speed a. before damping oscillations b. after damping oscillations c. beyond the rated frequency d. at constant power region 186. How many Thyristors are required to construct a load commutated inverter for Synchronous motor Drive a. 3 b. 6 c. 12 d. 24 187. In variable frequency control of synchronous motor drive the machine settles at new speed a. before damping oscillations b. after damping oscillations c. beyond the rated frequency d. at constant power region 188. How many Thyristors are required to construct a load commutated inverter for Synchronous motor Drive a. 3 b. 6 c. 12 d. 24 189. In load commutated Inverter fed Synchronous motor Commutation lead angle=180- αl, to a. take care of commutation over lap b. take care of commutation failure c. take care of triggering of thyristors d. take care of short circuit occurrences 190. In load commutated Inverter fed Synchronous motor, relation between phase current Is and DC link current Id a. b. c. d. 191. In load commutated Inverter fed Synchronous motor there will ____ no. of converter sets a. 3 b. 6 c. 2 d. 24 192. In load commutated Inverter fed Synchronous motor , motoring operation takes place when a. first set as inverter, second set as inverter b. first set as rectifier ,second set as inverter c. first set as inverter second set as rectifier d. at constant power region 193. In load commutated Inverter fed Synchronous motor , regenerative braking operation takes place when a. first set as inverter, second set as inverter b. first set as rectifier ,second set as inverter c. first set as inverter second set as rectifier d. at constant power region 194. In load commutated Inverter fed Synchronous motor, commutation lead angle β is equal to a. 90- α l b. 180-αl c. 90+ α l d. 180 + α l 195. In load commutated Inverter fed Synchronous motor, leading power factor operation is possible by a. adjusting frequency 16 of 18 10/16/2011 9:32 AM PED file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... b. adjusting excitation c. adjusting speed d. adjusting torque 196. In load commutated CSI fed Synchronous motor, source voltage is______ a. in series with a large value of inductor b. in series with a large value of capacitor c. in series with a small value of inductor d. in parallel with a large value of inductor 197. In Closed loop control of load commutated CSI fed Synchronous motor, four quadrant operation with regenerative braking is adoptable a. below 100MW b. beyond 100MW c. equal to 100MW d. above 1000MW 198. For high a. b. c. d. speed and high power drives ________ motors are used CSI fed Synchronous motor VSI fed Synchronous motor Cyclo converter fed Synchronous motor CSI fed Induction motor 199. Cyclo converter fed Synchronous motors are permissible for______________ a. high speed, high frequency b. low speed, low frequency c. high speed, low frequency d. low speed , high frequency 200. For Cyclo converter fed Synchronous motors, operation is possible in____ no. of quadrants a. 3 b. 1 c. 2 d. 4 201. A VSI feeding a Synchronous motor can be____________ a. Separately controlled Synchronous motor b. Self controlled Synchronous motor c. either a or b d. 202. In High rating blowers ____________ motors are used a. VSI fed Synchronous motor b. CSI fed Synchronous motor c. Cyclo converter fed Synchronous motor d. CSI fed Induction motor 203. In High rating Conveyers ____________ motors are used a. CSI fed Synchronous motor b. VSI fed Synchronous motor c. Cyclo converter fed Synchronous motor d. CSI fed Induction motor 204. In main line traction______________ motors are used a. Cyclo converter fed Synchronous motor b. VSI fed Synchronous motor c. CSI fed Synchronous motor d. CSI fed Induction motor 205. In Cyclo a. b. c. d. converter fed Synchronous motor, the out put frequency is limited to____ of input frequency 1/3 1/ 6 1/ 2 up to input frequency 206. In load commutated Cyclo converter fed Synchronous motors, line power factor _____ a. is unity b. is poor c. is leading d. is zero 207. For stepdown Cyclo converter fed Synchronous motors, thyristors are commutated by_____ a. line commutation b. forced commutation c. voltage commutation 17 of 18 10/16/2011 9:32 AM PED file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... d. resonant commutation 208. For low speed and low frequency,higher power rating machines are preferred _____type of motor a. Cyclo converter fed Synchronous motor b. VSI fed Synchronous motor c. CSI fed Synchronous motor d. CSI fed Induction moto 209. For low speed and low frequency,higher power rating machines are preferred _____type of motor a. Cyclo converter fed Synchronous motor b. VSI fed Synchronous motor c. CSI fed Synchronous motor d. CSI fed Induction moto 18 of 18 10/16/2011 9:32 AM EDS file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... JNTU ONLINE EXAMINATIONS [Mid 2 - EDS] 1. In a 3-phase, 10MVA, 11KV generator having 12% subtransient reactance, a 3-phase short-circuit occurs at its terminals, the fault current will be a. 9090A b. 5250A c. 3030A d. 2650A 2. Which portion of the power system is least prone to faults? a. Alternators b. Switchgear c. Transformers d. Overhead lines 3. The magnitude of fault current depends upon a. total impedance upto fault b. voltage at the fault point c. load current being supplied before occurrence of fault d. both total impedance upto fault and voltage at the fault point 4. A short-circuit current is identified by a. heavy current flow b. voltage rise c. voltage drop d. light current flow 5. Short-circuit currents are due to a. single phase to earth fault b. phase to phase fault c. all the three phases to earth fault d. all the three phases short-circuited 6. The most serious consequence of a major uncleared short-circuit fault could be a. blowing of fuse b. fire c. heavy voltage drop d. light voltage drop 7. Which of a. b. c. d. the following results in symmetrical fault? Single phase to earth Phase to phase All the three phases to earth Two phases to earth 8. Which portion of the transmission system is more prone to faults? a. Alternator b. Transformer c. Overhead lines d. Underground cable 9. In a star-connencted system without neutral grounding, zero sequence currents are a. zero b. vector sum of phase currents c. same as rms value of phase currents d. same as peak value of phase currents 10. In case of an unbalanced star-connected load supplied from an unbalanced 3-phase, 3-wire system, load currents will consist of a. positive sequence components b. negative sequence components c. zero sequence components d. positive sequence components and negative sequence components 11. Series reactors are used to a. improve the transmission efficiency b. improve the power factor of the power system c. improve the voltage regulation d. bring down the fault level within the capacity of the switchgear 12. The per unit impedance of a circuit element is 0.15. If the base KV and base MVA are halved, then the new value of the per unit impedance of the circuit element will be 1 of 12 10/16/2011 9:32 AM EDS file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... a. b. c. d. 0.075 0.15 0.30 0.60 13. A balance 3-phase system consists of a. zero sequence currents only b. positive sequence currents only c. negative and zero sequence currents d. zero, negative and positive sequence currents 14. Series reactors are installed at strategic locations in a power system so as to a. discharge the capacitors b. pass neutralizing surges of opposite nature c. directly pass the fault surges to the ground d. not related to recators 15. A power system network with a capacity of 100MVA has a source impedance of 10% at a point. The fault level at that point is a. 10MVA b. 30MVA c. 300MVA d. 1000MVA 16. Zero sequence component in 3 phases voltage of delta is a. line voltage b. zero c. line voltage3 d. line voltage/3 17. The arcing contacts for a circuit are made of a. copper tungsten alloy b. stainless steel c. hard pressed carbon d. aluminium alloy 18. Minimum arcing voltage will be the least in case of a. carbon b. copper c. silver d. tungsten 19. Circuit breakers usually operate under a. steady-state short-circuit current b. sub-transient state of short-circuit current c. transient state of short-circuit current d. square of the current 20. On occurrence of fault on the connected circuit, a circuit breaker operates a. manually b. automatically c. manually through a control switch d. depending upon the circuit breaker design 21. Current limiting reactors may be a. air-cored air cooled b. oil immersed magnetically shielded c. oil immersed non-magnetically shielded d. both air-cored air cooled and oil immersed magnetically shielded 22. The least expensive protection for over-current in low voltage system is a. rewirable b. upto 22kv c. upto 33kv d. above 33kv 23. A circuit a. b. c. d. breaker is essentially an are extinguisher a current interrupting device a power factor correcting device a device for neutralizing the effects of transients 24. The recovery voltage will be maximum for power factor of a. zero b. 0.5 2 of 12 10/16/2011 9:32 AM EDS file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... c. 0.707 d. unity 25. In a circuit breaker the current that exists at the instant of contact separation is called the a. restriking current b. breaking current c. arc current d. recovery current 26. The resistance of an electric arc can be increased by a. increasing the concentration of ionized particles b. reducing the arc length c. splitting the arc d. increasing the arc x-section 27. In a circuit breaker, the active recovery voltage depends upon a. circuit conditions b. power factor c. armature reaction d. voltage 28. The rate a. b. c. d. 29. Which of a. b. c. d. 30. With the a. b. c. d. 31. Sparking a. b. c. d. of rise of restriking voltage (RRRV) depends upon system voltage circuit pf only switching condition only both system voltage and circuit pf only the following contact point metals has the highest melting point? Tungsten Silver Copper Aluminium increase in mechanical force applied, the contact resistance remains unaltered increases decreases unpredictable occurs on switching-off the load due to circuit high resistance capacitance inductance skin effect 32. Compared to the breaking capacity of circuit breaker its making capacity should normally be a. more b. equal c. less d. the two are unrelated to each other 33. Fault diverters are basically a. circuit breakers b. fast switches c. fuses d. relays 34. The trip coil of a circuit breaker is connected through a CT of ratio 50:1.If the normal line current is 160 A and circuit breaker is to operate at 125% normal line current, the trip mechanism should be set to operate at trip current of a. 3.2A b. 4A c. 5A d. 15A 35. Breaking a. b. c. d. capacity of circuit breakers is usually expressed in MVA MW Kilo-amperes KV 36. The rating of a circuit breaker is usually determined on the basis of a. symmetrical fault current b. line to line fault current c. single line to ground fault current 3 of 12 10/16/2011 9:32 AM EDS file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... d. double line to ground fault current 37. Air blast a. b. c. d. circuit breakers employed for 400kv power system are designed to operate in 0.1s 50ms 10ms 200 µs 38. The pressure of air used in air blast circuit breaker is around a. 1kg/cm 2 b. 10kg/cm 2 c. 20kg/cm2 d. 100kg/cm 2 39. The zero a. b. c. d. sequence impedance of different elements of power system is equal not equal different more than one 40. The primary function of a fuse is to a. open the circuit b. protect the appliance c. protect the line d. prevent excessive currents from flow through the circuit 41. Operation of fuse is based upon a. photo-electric effect b. heating effect of electric current c. magnetic effect of electric current d. on voltage of the circuit 42. The fuse a. b. c. d. blows off by arcing burning melting absorbing 43. An isolator is installed a. to isolate one portion of the circuit from another b. usually on both sides of a circuit breaker c. as a substitute for a circuit breaker d. both to isolate one portion of the circuit from another and usually on both sides of a circuit breaker 44. A fuse is a. b. c. d. normally a power limiting device voltage limiting device current limiting device power factor correcting device 45. Fuses have got advantages of a. cheapest type of protection b. inverse time-current characteristic c. no maintenance d. Cheaper, inverse time current characteristic and no maintance 46. A fuse is a. b. c. d. 47. A fuse is a. b. c. d. always connected in series with the circuit always connected in parallel with the circuit normally connected in series with the circuit normally connected in parallel with the circuit normally inserted in phase wire normally inserted in neutral wire never inserted in neutral wire never inserted in phase wire 48. The material used in liquid fuses is a. SF6 b. distilled water c. carbon tetra chloride d. transformer oil 4 of 12 10/16/2011 9:32 AM EDS file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... 49. Which of a. b. c. d. the following materials is more susceptible to oxidation? Silver Copper Tin and lead alloy iron 50. Re wirable fuse has a. inverse time current characteristic b. linear time-current characteristic c. square law time-current characteristic d. non linear time current chrematistics 51. Protection by fuses is generally not used beyond a. 200A b. 50A c. 25A d. 10A 52. A fuse in a. b. c. d. a motor circuit provides protection against short-circuit over-load open circuit short-circuit and overload 53. Operating time for fuse wire is about a. 0.1 ms b. 2ms c. 0.1s d. few seconds 54. The material used for fuse wire should be of a. low resistivity and high melting point b. high resistivity and high melting point c. high resistivity and low melting point d. low resistivity and low melting point 55. A material best suited for manufacturing of fuse wire is a. silver b. copper c. aluminium d. zinc 56. Over-current protection respond to a. increase in current above pick-up value b. single line to earth faults c. double line to earth faults d. line to line to fault 57. A relay used on short transmission lines is a. mho relay b. reactance relay c. impedance relay d. admittance relay 58. HRC fuses provide best protection against a. over load b. short-circuits c. open circuits d. reverse current 59. The rating of fuse is expressed in terms of a. amperes b. volts c. VAR d. kva 60. The delay fuses are used for protection of a. light circuits b. motors c. fluorescent lamp d. transformers 61. In comparison to rewirable fuses HRC fuses have the advantages of a. high speed operation b. high rupturing capacity 5 of 12 10/16/2011 9:32 AM EDS file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... c. no ageing effect d. high reliable 62. HRC fuses provide best protection against a. short-circuit b. lightning c. sparking d. fire 63. A lightning arrester connected between the line and earth in a power system a. protects the terminal equipment against traveling surges b. protects the terminal equipment against direct lightning stroke c. suppresses high frequency oscillations in the line d. reflects back the traveling waves approaching it 64. Basically a. b. c. d. a lightning arrester is a surge absorber surge diverter surge reflector light emmiter 65. A lightning arrester provides a. low impedance path b. high impedance path c. low resistance path d. high resistance path between line and earth during operation 66. The most commonly used method for the protection of 3-phase feeder is a. time graded protection b. differential protection c. reverse power protection d. scalar protection 67. Earth wires are made of a. copper b. aluminium c. iron d. galvanized stranded steel 68. For an open-circuited transmission line, the reflection coefficient is a. 1 b. -1 c. zero d. 0.7 69. For a short-circuited transmission line, the reflection coefficient is a. 1 b. -1 c. zero d. 0.5 70. High current flow in transmission system causes a. Increased power losses b. decreased power losses c. not effect on power losses d. power losses constant 71. Shunt compensation normally done in a. short transmission system b. distribution system c. long transmission system d. medium transmission system 72. Series compensation normally done in a. A.C distribution system b. D.C distribution system c. long transmission system d. short transmission system 73. Neutral earthing is provided for a. the safety of personnel from electric shock b. the safety of equipment and personnel against lightning and voltage surges c. reducing the voltage stress on lines and equipment with respect to earth under various operating and fault conditions d. controlling the earth fault currents for protective relaying 6 of 12 10/16/2011 9:32 AM EDS file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... 74. The advantage of neutral earthing is a. safety of personnel b. reduction of earth fault current c. elimination of arcing ground d. reliability 75. Grounding is done generally at a. receiving end b. supply end c. either at receiving end or at supply end d. at mid point 76. Solid earthing is done for voltage below a. 400V b. 600V c. 11kv d. 66kv 77. A 400V, 50Hz, 3-phase supply delivers 207kW at 0.8 p.f. lagging. It is desired to bring the line p.f. to unity by installing shunt capacitors. Calculate the capacitance if they are star connected a. 3.09 µF b. 4µF c. 5µF d. 6µF 78. Find the rating of the capacitor required to improve the power factor of an induction motor from 0.65 to 0.85 lag. The motor takes 4kW a. 150 µF b. 132 .2 µF c. 140 µF d. 100 µF 79. The net savings function (S) in capacitor placement is given by a. Maximize, S= KE-KC b. Maximize, S= KE-KC c. S= KE+KC d. Maximize, S= KE+KC 80. A single phase motor takes a current of 10A at power factor of 0.707 lagging from a 230V, 50Hz supply. What value must a shunting capacitor have to raise the power to unity? a. 100 µF b. 97.85 µF c. 125 µF d. 94.5 µF 81. The reactive power flow can be controlled by installing shunt-compensating devices at a. load b. source c. mid point d. generation 82. Shunt capacitors raise the a. load power factor b. transmission line power factor c. generation power factor d. does not effect power factor 83. The size a. b. c. d. of capacitors can be determined based on the Objective function net consuming net saving loss reduction efficiency 84. The problem of capacitor placement can be divided in to a. capacitor sizes only b. optimum locations only c. capacitor sizes at the optimum locations d. to reduce losses 85. Electro-mechanical voltage regulators are used in a. alternators b. transformers c. transmission d. motors 7 of 12 10/16/2011 9:32 AM EDS file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... 86. A 400V, 50Hz, 3-phase supply delivers 207kW at 0.8 p.f. lagging. It is desired to bring the line p.f. to unity by installing shunt capacitors. Calculate the capacitance if they are delta connected. a. 12 µF b. 1.03µF c. 3 µF d. 4 µF 87. Find the reactive power supplied by the capacitor to improve the power factor of motor from 0.65 to 0.85 lag. The motor draws 4 kw. a. 100 KVAR b. 150 KVAR c. 200 KVAR d. 2.197KVAR 88. Loss saving equation after installing capacitor bank is a. b. c. d. 89. The process of selecting a protecting device during the faculty condition is known as a. series operation b. parallel operation c. co-ordination d. non co-ordination 90. The device which operates first while clearing the faulty condition is known as a. protected device b. protecting device c. back up device d. primary device 91. Induction regulators are employed for voltage control in a. distribution systems b. transmission lines c. alternators d. motors 92. For voltage control in ac distribution system the induction regulators have the advantages of a. reliability of operation b. operation independent of load and power factor variations c. step less voltage variations without arcing or short circuiting of turns as in the case of transformers d. reliability and independent for load and power factor variations 93. Which of a. b. c. d. the following is a static exciter? Rotorol Amplidyne Rectifier Metadyne 94. Tap changing transformers are employed for a. stepping down the voltage b. stepping up the voltage c. supplying low voltage current to instruments d. both stepping up and stepping down the voltage 95. In tap changing transformers, the tappings are provided on a. secondary winding b. primary winding c. tertiary winding d. high voltage winding 96. The best a. b. c. d. location for use of a booster transformer in a transmission line is at the sending end at the receiving end at the intermediate point anywhere in the line 97. Line drop compensator is a a. feeder b. voltage regulator c. distributor d. protecting device 98. Distribution type voltage regulators are 8 of 12 10/16/2011 9:32 AM EDS file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... a. b. c. d. single phase only three phase only both single phase and three phase three phase four wire 99. Line sectionalizer is a a. primary device b. back up device c. not a power system apparatus d. distribution device 100. Line sectionalizers are in the range of a. 5 to 50A b. 10 to 100A c. 10 to 600A d. 50 to 500A 101. The device which operates after operation of protecting device is known as a. protected device b. protecting device c. back up device d. primary device 102. The main objective of distribution system is a. to minimize the number of consumers effected b. to minimize the duration of fault c. To localize the fault d. to extend the fault 103. The secondary objective of distribution system protection is a. to eliminate the safety hazards b. to manage the faulty line c. to eliminate the service outages d. to minimize the service outages 104. Temporary faults are in the range of total faults a. 60% b. 75to 90% c. 90 to 100% d. 5 to 50% 105. In order a. b. c. d. to determine the size of capacitor __________ curve is used load curve capacitance curve capacitive load duration curve reactive load duration curve 106. To increase the reliability of voltage improvement ________ type of capacitors are preferred a. fixed b. Switched c. mixed d. static 107. Normally fixed capacitors are installed upto the kvar of a. 400 b. 300 c. 600 d. 200 108. Most type of control used for the switched capacitor is a. voltage control b. current control c. time control d. capacitance control 109. Station type voltage regulators are a. single phase only b. three phase only c. both single phase and three phase d. three phase four wire 110. Step type voltage regulators are a. Auto transformers b. capacitors c. synchronous condensers 9 of 12 10/16/2011 9:32 AM EDS file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... d. at alternators only used 111. Three phase step type voltage regulators are in the size of a. 100 to 1000 kva b. 500 to 2000 kva c. 300 to 1300 kva d. 50 to 150 kva 112. The excitation control is only suitable for a. short lines b. medium lines c. long lines d. intermittent lines 113. The principle cause of voltage variation is the change of _________ system a. current b. load c. power d. inductance 114. The voltage regulation in the brown and bovery regulator should not exceed a. ±2% b. ±1% c. ±4% d. ±3% 115. A synchronous condenser normally installed at a. sending end b. at mid point c. receiving end d. at bus bar 116. Automatic circuit recloser is a a. primary device b. back up device c. not a power system apparatus d. distribution device 117. TCC of a a. b. c. d. fuse is a time curves time current characteristics torque current characteristics torque curves 118. The melting time of fuse should be a. low b. high c. medium d. does not depend on time 119. Automatic circuit recloser is a a. it requires operator to recluse b. it recluses the circuit automatically c. it is not a protecting device d. it is a back up device 120. In a balanced 3-phase system negative and zero sequence currents are a. zero b. more than one c. less than one d. infinity 121. In a 3-phase 4 wire un balance system, the magnitude of zero sequence current is ________ of the current in the neutral a. one third b. one fourth c. half d. one fifth 122. The most common type of unsymmetrical fault is a. L-G b. LL-G c. 3 phase d. L-L 10 of 12 10/16/2011 9:32 AM EDS file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... 123. The most dangerous type of unsymmetrical fault is a. L-G b. LL-G c. 3 phase d. L-L 124. In practice, tap changing is preferred on load so that there is _________ to supply a. interruption b. no interruption c. quality d. eliability 125. Normally tap changing is done a. with out load b. with switch off supply c. with load d. it does not depends on load 126. Voltage control equipment is used in ___________ in the power system a. at sending end b. at receiving end c. at more than one point d. at one point 127. In feeders _________ type of voltage regulators are used a. distribution type b. station type c. induction type d. feeder type 128. It is desired to correct the power factor to 0.95 by means of static capacitors connected across each phase of a 3-phase, 400V, 50Hz motor installation having a maximum load of 50KVA at a power factor of 0.75. What is the leading KVAR supplied by the capacitor bank. a. 20.75 b. 25 c. 30 d. 50 129. A synchronous motor having a power consumption of 50kW is connected in parallel with a load of 200kW at a p.f. 0f 0.8 lag. The excitation of the motor is adjusted until combined p.f. becomes 0.9 lag. Calculate the KVA input of the motor. a. 57.76 b. 60 c. 100 d. 150 130. A 3-phase 5kW induction motor has a power factor of 0.75 lagging. A bank of capacitors is connected in delta across the supply terminals and p.f. raised to 0.9 lagging. Determine leading kVAR supplied by capacitor bank. Assume efficiency 100% a. 5 b. 1.99 c. 3 d. 4 131. It is desired to correct the power factor to 0.95 by means of static capacitors connected across each phase of a 3-phase, 400V, 50Hz motor installation having a maximum load of 50KVA at a power factor of 0.75. What must be the capacity of each delta connected condenser? a. 100 µF b. 200 µF c. 238 µF d. 400 µF 132. The positive sequence impedance of the transmission line is _______ to the negative sequence impedance a. not equal b. equal c. less than one d. more than one 133. A workshop is consuming 500kW at 0.707 power factor lagging. A synchronous motor is connected to improve the power factor to 0.95 lagging. If the synchronous motor takes 100kW. Find its power factor. a. 0.5 b. 0.285 11 of 12 10/16/2011 9:32 AM EDS file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... c. 0.4 d. 0.6 134. A workshop is consuming 500kW at 0.707 power factor lagging. A synchronous motor is connected to improve the power factor to 0.95 lagging. If the synchronous motor takes 100kW. Find the reactive KVAR supplied by the motor. a. 400 b. 500 c. 336 d. 800 135. A 3-phase 5kW induction motor has a power factor of 0.75 lagging. A bank of capacitors is connected in delta across the supply terminals and p.f. raised to 0.9 lagging. Determine kVAR rating of capacitors connected in each phase. Assume η =100%. a. 0.4 b. 0.663 c. 0.7 d. 0.8 136. Series compensation on EHV lines is resorted to a. Improve the stability b. Reduce the fault level c. improve the voltage profile d. As a substitute for synchronous phase modifier 137. A synchronous phase modifier as compared to a synchronous motor used for mechanical loads has a. larger shaft and higher speed b. smaller shaft and higher speed c. larger shaft and smaller speed d. smaller shaft and smaller speed 138. A synchronous motor having a power consumption of 50kW is connected in parallel with a load of 200kW at a p.f. 0f 0.8 lag. The excitation of the motor is adjusted until combined p.f. becomes 0.9 lag. Calculate power factor of the motor. a. 0.8 lag b. 0.86 lag c. 0.8655 lead d. 0.9 lead 139. A single phase 400V, 50Hz, motor takes a supply current of 100A at power factor of 0.701 lag. The motor power factor has been improved to 0.9 lagging by connecting a condenser in parallel. Calculate the capacity of the capacitor. a. 100 µF b. 150 µF c. 291 µF d. 130 µF 140. Phase modifier is normally installed in the case of a. short lines b. medium lines c. long lines d. for all length lines 141. For complete protection of a three phase line a. Three phase and three earth fault relays are required b. Three phase and two earth fault relays are required c. Two phase and two earth fault relays are required d. Two phase and one earth fault relays are required 142. A single phase 400V, 50Hz, motor takes a supply current of 100A at power factor of 0.701 lag. The motor power factor has been improved to 0.9 lagging by connecting a condenser in parallel. Calculate the current through capacitor a. 100 A b. 150 A c. 36.47 A d. 119 A 143. For the same voltage boost, the reactive power capacity is more for a a. shunt capacitor b. series capacitor c. it is same for both series and shunt d. it is not depends on capacitor 12 of 12 10/16/2011 9:32 AM PSA file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... JNTU ONLINE EXAMINATIONS [Mid 2 - PSA] 1. A 1000 kVA transformer with 5% reactance will have a reactance of 10% at____ a. 1000 kVA base b. 2000 kVA base c. 3000kVA base d. 4000 kVA 2. The p.u. impedance value of an alternator corresponding to base values of 13.2kV and 30MVA is 0.2p.u. The p.u. value for the base values 13.8kV and 50MVA is _______ a. 0.106 p.u. b. 0.206 p.u c. 0.306 p.u d. 0.318 p.u 3. A Transformer has reactance of 4% on a 20 MVA base. For 30 MVA base reactance is________ a. 6% b. 2.66 % c. 9 % d. 2% 4. The p.u impedance of a line to a 50 MVA. 132 kV base is 0.6. The p.u impedance to a 100 MVA , 132 kV base will be a. 0.3 b. 0.6 c. 1.2 d. 1.8 5. Base impedance of the power system is given by a. b. c. d. 6. If base values are 50 MVA and 11kV, the base impedance is ______ohms a. 4.54 b. 0.22 c. 27 d. 1 7. If per unit impedance on 11kV base is 9 ohms, the p.u impedance on 33kV base will be ____ohms a. 3 b. 81 c. 27 d. 1 8. The correct formula to convert actual impedance Z ohms to p.u impedance is a. b. c. d. 9. In a _______ the components of power system are represented by symbols and the interconnection between them are shown by straight lines. a. Single line diagram b. Impedance diagram c. Reactance diagram d. Resistance diagram 10. The positive, negative and zero sequence impedances of a solidly grounded system under steady state condition always follow the relations a. Z 1>Z2>Z0 b. Z1<Z2<Z0 c. Z0<Z1<Z2 d. Z0<Z1>Z2 11. Symmetrical components are a. balanced three-phase vectors b. unbalanced three phase vectors c. depends upon the original configuration d. depends upon the modified configuration 1 of 13 10/16/2011 9:31 AM PSA file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... 12. In a balanced three phase system, negative and zero phase sequence currents are a. equal b. zero c. different d. one 13. For a balanced 3-Phase system the ______ is same as positive sequence reactance diagram a. Single line diagram b. Impedance diagram c. Reactance diagram d. Resistance diagram 14. The per unit quantity is defined as a. Actual /Base b. (Base) / Actual c. Base / (Actual-1) d. Base / (Actual-2) 15. The operator 'a' rotates the vector in the anti clock wise direction by a. 900 b. 1200 c. 1800 d. 3000 16. Which of the following is correct a. 1+a+a2 =0 b. a+2=1 c. 1+ 3=0 d. 1+ 2=0 17. Which of the following is correct a. 1+a+a2 =0 b. a+2=1 c. 1+ 3=0 d. 1+ 2=0 18. Which of the following is correct a. a2=0.5+j0.866 b. a2=-0.5+j0.866 c. a2=-0.5-j0.866 d. a2=j0.866 19. The positive and negative sequence impedance of a transmission line are a. Equal b. zero c. different d. one 20. The zero a. b. c. d. sequence impedance of different elements of power system is generally Equal zero different one 21. On the occurrence of the unsymmetrical fault which sequence component is always more than the negative sequence component a. Zero sequence b. positive sequence c. Zero sequence, positive sequence d. one 22. The zero a. b. c. d. sequence impedance of an element in a power system is generally different from Positive sequence impedance negative sequence impedance Positive and negative sequence impedances Positive sequence resistance 23. If the percentage reactance of the system up to the fault point is 20 % and the base kVA is 10000 then the short circuit kVA is a. 10 MVA b. 20 MVA 2 of 13 10/16/2011 9:31 AM PSA file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... c. 50 MVA d. 60 MVA 24. The indicative of unsymmetrical in the system can be a. the presence of the negative sequence components b. the presence of positive sequence components c. the presence of zero sequence components d. the presence of the negative and zero sequence components 25. For an unbalanced three phase system a. Z 2=Z 0=infinite b. Z 1>Z 2>Z 0 c. Z 1=Z 2=Z 0=0 d. Z 1>Z 2<Z 0 26. On the occurrence of the unsymmetrical fault which sequence component is always more then the negative sequence component a. Zero sequence b. positive sequence c. Zero and positive sequence d. negative sequence 27. The phase sequence of the positive sequence component is abc, then the phase sequence of the negative sequence components will be a. abc b. acb c. bac d. cab 28. The most common type of fault on the over head transmission line is a. Single line to ground fault b. double line to ground fault c. Three-phase fault d. line to line fault 29. Which fault gives rise to symmetrical fault currents? a. single line to ground fault b. line to line fault c. double line to ground fault d. three-phase fault 30. The positive sequence component of voltage at the point of fault is zero when it is a. Three phase fault b. L-L fault c. L-L-G fault d. L-G fault 31. A balanced star connected load takes I amperes from a balanced 3-phase 4-wire system .The 3-phase are provided with fuses .If the fuse in Y and B phases are removed then a. I R=I b. I y=0 c. I B=0 d. IR=I, Iy= IB=0 32. If neutral to ground impedance is greater than 1/3 (Z1-Z0 )then a. 3-phase fault is more severe than L-G fault b. L-G fault is more than 3-phase fault c. the ratio of severity is 1:1 d. the ratio of severity is 1:2 33. .For a long transmission line a. 3-phase fault is more severe than L-G fault b. L-G fault is more severe than 3-phase fault c. Effect of both L-G and 3-phase fault is same d. 3-phase fault is less severe than L-G fault 34. The current from the neutral to ground is 6A. the zero sequence current in phase will be a. 18 A b. 6A c. 2 A d. 4A 35. A balanced star connected load takes I amperes from a balanced 3-phase 4-wire system .The 3-phase are provided with fuses .If the fuse in Y and B phases are removed ,which of the following is not 3 of 13 10/16/2011 9:31 AM PSA file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... correct a. b. c. d. positive sequence currents are not zero negative sequence currents are not zero zero sequence currents are not zero zero sequence current magnitude is 1/3 rd of I 36. If a neutral impedance of Z0=1/3 (Z1-Z0) is included between neutral to ground .Then the ratio of L-G fault current to dead short circuit is a. 1:1 b. 1:2 c. 1:3 d. 3:1 37. For a synchronous machine with solidly grounded neutral a. Z 0<Z 1 b. Z 0>Z 1 c. Z 1=Z 2=Z 0 d. Z 0>Z 2 38. For a synchronous machine with solidly grounded neutral a. a L-G fault is more severe than 3-phase fault b. 3-phase fault is more severe than L-G fault c. both L-G and 3-phase faults have the same effect d. 3-phase fault is less severe than L-G fault 39. A double a. b. c. d. line to ground fault is characterized as symmetrical fault unsymmetrical fault symmetrical voltage symmetrical current 40. The method of symmetrical components is used to analyze the unsymmetrical faults, because a. Un balanced currents b. Un balanced voltages c. Un balanced powers d. Un balanced currents, voltages and powers 41. The positive sequence voltage (Va1)for a particular fault is zero the fault is a. LG b. LL c. LLG d. 3- phase 42. The positive sequence component of voltage at the point of fault is zero when it is a. Three phase fault b. L-L fault c. L-L-G fault d. L-G fault 43. The faults can be classified as _______ a. shunt faults b. series faults c. shunt and series faults d. open faults 44. Shunt type of faults involves ___________ between the conductors. a. power conductors b. conductors-to-ground c. short circuit d. power conductors, conductors-to-ground and short circuit 45. Series type of faults is characterized by ________ in current and ______ in voltage. a. increase, decrease b. decrease ,increase c. increase, increase d. decrease , decrease 46. Shunt type of faults can be classified as _______ a. L-L b. L-L-G c. L-G d. L-L, L-L-G and L-G 47. The example for balanced fault is ________. 4 of 13 10/16/2011 9:31 AM PSA file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... a. b. c. d. L-L L-L-G L-G 3-Φ;. 48. Series type of faults can be classified as _______. a. Opening of line b. L-L fault c. L-L-G fault d. L-G fault 49. For fault a. b. c. d. analysis of large power systems, the most suitable method isBus impedance method Bus admittance method Bus current method Bus impedance method Bus voltage method 50. The three sequence equations using the sequence generated voltages and the sequence impedances are a. b. c. d. 51. The voltage of the neutral is given by Vn= a. 3I ao Zn b. - 3Iao Zn c. I ao Z d. I ao Zn 52. In case of L-G fault, the three sequence networks are connected in a. Series b. parallel c. shunt d. series and parallel 53. The analysis of unsymmetrical faults by symmetrical components method requires the determination of a. Sequence voltages b. Sequence currents c. Sequence powers d. Sequence voltages , Sequence currents and Sequence powers 54. The positive and negative components of currents through the neutral are a. zero b. 1 c. 2 d. 1.5 55. In case of L-G fault, the expression for the current Ia1= a. b. c. d. 56. The negative and zero sequence voltages are maximum at ______and minimum at _____ a. fault point , fault point b. neutral point , neutral bus c. fault point , fault bus d. fault point , neutral bus 57. The receiving end voltage is equal to sending end voltage for a loss less line condition for maximum power is a. x = 1.732R b. x = 1.414R c. x = 1.732/R d. x = 1.732+R 58. If the torque angle increases without limit, the system is ___ a. stable b. unstable c. marginally stable d. oscillates 5 of 13 10/16/2011 9:31 AM PSA file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... 59. For L-L fault, the positive-sequence and negative-sequence networks are connected in a. same b. parallel c. opposition d. series 60. In case of L-G fault, the expression for the fault current is given by If = a. 4 I a1 b. 2 I a1 c. I a1 d. 3 Ia1 61. For L-L fault, the zero-sequence component of current is a. 1 b. zero c. 1.5 d. 0.3 62. For L-L fault, the positive-sequence component of voltage is equal to the negative-sequence component of a. voltage b. current c. impedance d. resistance 63. Fast operating CB s improves a. Steady state stability b. Transient stability c. Steady state and transient stability d. load flows 64. The angle between relative position of rotor axis and the stator magnetic field axis is a. Load angle b. Torque angle c. Load angle or Torque angle d. Steady state stability 65. In a two-machine system , ______ grounding at the sending end and ____ grounding at the receiving end is preferable a. Resistance, Reactance b. Reactance, Resistance c. Resistance, Resistance d. Reactance, Reactance 66. If the maximum power =50MW, the electrical power out power for a torque angle of 600 is _____ a. 43.7MW b. 43.4MW c. 43.6MW d. 43.3MW 67. Maximum Steady state limit of power system operates with a. <450 b. 300 c. 900 d. <900 68. If transmitted power is increased beyond____ then the synchronism will be lost a. Steady state stability limit b. Transient stability limit c. Steady state and transient stability limits d. dynamic stability limit 69. A system is said to be ____ if and only if dp/dd is positive a. Marginally stable b. Unstable c. Stable d. oscillates 70. If a two-machine are running coherently with inertia M1 and M2.What will be the inertia of the equivalent machine Meq a. {(M1S1)/Sb}+{(M2S2)/Sb} b. {(M1S 1)/S b}-{(M2S 2)/S b c. (M1S 1) + (M2S 2) 6 of 13 10/16/2011 9:31 AM PSA file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... d. (M1S 1) - (M2S 2) 71. Two synchronous machine having inertia constant M1 and M2 are swinging together. The inertia constant of the combination is a. M1M2 /(M1+M2) b. M1-M2/(M1+M2) c. M1M2 /(M1-M2) d. M1+M2/(M1-M2) 72. The series capacitor improves a. Steady state stability limit b. Transient stability limit c. Steady state and transient stability limits d. Dynamic stability 73. If loading of machine is large, the torque angle will be a. more b. less c. constant d. twice 74. For stability and economic reasons, we operate the transmission line with load angle in the range a. 300 b. 450 c. 300- 450 d. 300- 900 75. In terms a. b. c. d. of system stability point of view, the star point of the motor is ____ grounded Reactance Reactance impedance admittance 76. From the stability point of view, the star point of the generator is ____ grounded a. Reactance b. Reactance c. Resistance& Resistance d. Reactance or Reactance 77. A 12 pole, 300 rpm, 11kV, 3-phase alternator has a stored energy of 5400MJ. Its a. 4 b. 9 c. 10 d. 0.1 78. Two alternator with stored energies of 1200MJ and 1000MJ are working is Parallel. Its equivalent inertia constant for the base 100MVA is (in MJ/MVA) a. 120 b. 220 c. 12 d. 22 79. If the maximum power =50.2MW, The electrical power out power for a torque angle of 660 is _____ a. 43.7MW b. 43.4MW c. 45.86MW d. 15MW 80. Switching of asynchronous loads effect a. voltage stability b. frequency stability c. power system stability d. voltage and frequency stability 81. Loss of synchronism leads to a. system stability b. system unstable c. oscillatory d. marginally stable 82. When a system reaches stable state followed by a large disturbance it is referred to as a. Steady state stability b. Transient stability c. power system stability 7 of 13 10/16/2011 9:31 AM PSA file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... d. un stable 83. Classical a. b. c. d. 84. Which of a. b. c. d. approach of power system stability means Simplified model of synchronous machine no voltage regulators no dampers no booster the following is a small disturbance? sudden increase in load loss of generation switching of transmission line when initial power flow is small sudden drop of load 85. When a system reaches stable state followed by a small disturbance it is referred to as a. Steady state stability b. Transient stability c. power system stability d. dynamic stability 86. Simplified model of synchronous generator is represented by a. voltage source b. impedance c. voltage source and impedance in parallel d. voltage source and impedance in series 87. Power angle curve shows relation between a. Pm Vs Pe b. Pm Vs δ c. Pe Vs δ d. Pa Vs δ 88. The steady state stability can be improved by a. reducing reactance of line b. increasing excitation c. selecting low impedance machines d. reducing reactance of line, increasing excitation and selecting low impedance machines 89. For stability the change in δ w.r.t time i.e., dδ/dt= a. infinite b. one c. zero d. Pm-Pe 90. .When a a. b. c. d. sudden and large disturbance occurs, δ does not change if rotor runs at < synchronous speed > synchronous speed synchronous speed max speed 91. If the input of the generator is more than the output the torque angle will a. reduce b. increase c. be constant d. exponential 92. If the input of the motor is more than the output the torque angle will a. reduce b. increase c. be constant d. exponential 93. The loss a. b. c. d. of synchronism of machine results variation in frequency voltage power factor frequency and voltage 94. A 12 pole, 3000 rpm, 11kV, 3-phase alternator has a stored energy of 5400MJ. Its inertia is MJ-sec/elec.degrees is a. 4 b. 9 c. 10 d. 0.1 8 of 13 10/16/2011 9:31 AM PSA file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... 95. Equal area criteria can be applicable to a. multi machine system b. One machine connected to infinite bus c. One machine connected to multi bus system d. One machine connected to multi machine system 96. If the receiving end voltage is equal to sending end voltage for a loss less line, the condition for maximum power is a. b. c. X=R d. 97. If the torque angle increases without limit the system is a. Stable b. unstable c. oscillatory d. marginally stable 98. The solution of swing equation can be obtained by_____ method a. point by point b. equal area criterion c. Newton d. gauss method 99. The solution of swing equation gives a graph ______ Vs____ a. power , load angle b. Load angle, power c. Torque angle, time d. time, torque angle 100. The limit a. b. c. d. of steady state is ___ transient stability limit more than less than equal to greater than or equal to 101. The addition of synchronous motor (over excited) at the receiving end of a line improves ____ stability a. steady state stability b. dynamic stability c. transient stability d. dynamic and transient 102. Compared to short transmission line, a long transmission line with same operating voltage will have less steady state stability limit because ____ is high a. reactance b. resistance c. current d. admittance 103. A salient a. b. c. d. pole machine has relatively high stability limit during steady state stability limit because ___ synchronous power coefficient is high synchronous power coefficient is low synchronous power coefficient constant synchronous power coefficient is zero 104. The solution of the swing equation can be obtained by ______ method a. step-step b. equal area c. step-step and equal area d. Newton 105. Fast acting voltage regulators includes____ stability a. dynamic b. steady state c. transient d. voltage 106. The inertia constant of turbo alternator is _____ than hydro generators a. less b. more c. equal d. greater than equal 107. The series capacitor improves 9 of 13 10/16/2011 9:31 AM PSA file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... a. b. c. d. dynamic stability steady state stability transient stability dynamic and transient 108. If the actual clearing angle is greater than the critical value, the system is ____ , a. Marginally stable b. Unstable c. Stable d. Oscillatory 109. In point by point method, the computed swing curve approaches the true curve, only when the time interval is-----------a. Decreased b. Increased c. Constant d. zero 110. ----- machine stability will have more than one swing equation. This statement is a. Multi b. single c. single machine connected to infinite d. Infinite 111. The swing equation can be solved by _____ method a. Runge-kutta b. Modified Euler's c. Both Runge-kutta and Modified Euler's d. Newton 112. The solution of the swing equation gives a graph ______ Vs _______ a. Time Vs torque angle b. torque angle Vs angle c. torque angle Vs time d. power Vs time 113. The limit a. b. c. d. of transient stability is _____ the steady state limit { B} Greater than less than equal to greater than or equal 114. The solution of point by point method adopted to solve the swing equation for a. Power angle b. critical clearing time c. clearing angle d. clearing time 115. Equal area criterion can be applicable to a. three machine system b. One machine system connected to infinite bus c. four machine system d. five machine system 116. Multi machine stability will have ---- than one swing equation. This statement is a. more b. less c. equal d. infinite 117. Which one of the following is the swing equation a. (H/πf) (d2δ/dt2) = Pm-Pe b. (H/πf) / (d 2δ/dt2) = Pm+Pe c. (H/πf) / (d 2δ/dt2) = PmPe d. (πf/H) / (d 2δ/dt2) = Pm-Pe 118. The solution of swing equation gives the graph __ vs __ a. Torque angle, Time b. Time, Torque angle c. Torque angle, Voltage d. Time, Voltage 119. The swing equation describes 10 of 13 10/16/2011 9:31 AM PSA file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... a. b. c. d. rotation of rotor rotating magnetic field rotor oscillations rotor speed 120. Transient stability of a large scale power system can be improved by a. Increasing system voltage b. Decreasing system voltage c. increasing resistance d. increasing reactance 121. The swing equation is a. Md 2δ/dt2 b. Md 2δ/dt2=Tm-Te c. Md2�/dt2=Pm-Pe d. Md 2t/dδ2 122. The swing equation is used to determine a. Steady state stability b. Transient stability c. steady state & transient d. dynamic 123. The critical clearing angle of a SMIB through two transmission lines can be determined by using a. single power angle curve b. two power angle curves c. 3 power angle curves d. Pm vs Pe curve 124. Auto reclosing is possible in case of a. short period faults b. semi permanent faults c. permanent faults d. short period faults & semi permanent faults 125. The equal area criterion is applicable only to a. SMIB b. two machine system c. multi machine system d. SMIB & two machine system 126. The swing curve provides information of a. stability b. faulted conditions c. stability & fault conditions d. only stability 127. The transient stability is determined by a. analytical method b. step by step method c. equal area criterion d. step by step method or equal area criterion 128. In the equal area criterion if A2 129. stable 130. unstable 131. critically stable 132. stable or unstable The numerical methods are used to simulate a. b. c. d. power system stability faulted conditions stability & fault conditions only stability An alternator is capable of facing the problem of Hunting. It has a. good steady state stability b. good transient stability 11 of 13 10/16/2011 9:31 AM PSA file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... c. good dynamic stability d. load speed characteristics which are dropping The solution of point by point method adopted to solve swing equation gives a. b. c. d. critical clearing time clearing time clearing angle clearing angle & time The stability of transmission line can be improved by using a. b. c. d. lightning arrestors quick acting CB's fuses slow acting CB's The failure of excitation system affects a. b. c. d. steady state stability transient stability steady state and transient stabilities dynamic Normally power system operates a. <450 b. 300 c. 90 0 d. <900 The limit of transient stability is ___ than steady state limit a. b. c. d. less than more than equal a greater than equal The CB is supposed to operate before ____ to improve____ stability a. b. c. d. critical clearing time, transient critical clearing time, dynamic critical clearing time, steady state clearing time , steady state From the stability point of view, the star point of the generator is _____ grounded a. b. c. d. resistance reactance succeptance admittance From the stability point of view, the star point of the motor is _____ grounded a. b. c. d. reactance resistance succeptance admittance For stability and economic reasons we operate the transmission line with power angle in the range a. 300 to 450 b. 40 0 to 650 c. 65 0 to 900 d. 900 to 1800 If the torque angle is increases infinitely, the system will show a. b. c. d. unstable operation stable operation marginally stable critically stable 12 of 13 10/16/2011 9:31 AM PSA file:///C:/Documents and Settings/Sandeep/My Documents/Downloads/4... The auto recloser unit in a modern CB improves ______ stability limit a. b. c. d. transient steady state dynamic steady state & dynamic A generator is connected to a synchronous motor. From stability point of view the generator neutral is ___ grounded and motor terminal is _____ grounded a. b. c. d. resistance, reactance reactance, resistanc resistance, resistance reactance, reactance Two synchronous machines having inertia constants M1 and M2 are swing together. The inertia constant of the combination is a. b. c. d. 100MW when transferred as a maximum power, when line reactance is 1 ohm, the fault increases the reactance to 4 ohms> The new value of maximum power is a. b. c. d. 25MW 50 MW 75 MW 100 MW If two lines in parallel, working as inter connectors, one of them switches off the new value of steady state power will _______ because the line transfer reactance is_____ a. b. c. d. decreases, high decrease, low increase, high increase, low It is required to improve transient stability of power system. Pick out wrong method a. b. c. d. Use auto reclosing fast acting CB s use AVR operate heavy machines if possible reduce reactance A synchronous motor of negligible resistance receiving 25% of power that it is capable of receiving from an infinite bus. If the load is suddenly doubled, the new power angle is ____ degrees a. 300 b. 60 0 c. 90 0 d. 120 0 If the torque angle is increases infinitely, the system will show a. b. c. d. unstable operation stable operation marginally stable critically stable A synchronous motor of negligible resistance receiving 25% of power that it is capable of receiving from an infinite bus. If the load is suddenly doubled, the new power angle is ____ degrees a. 300 b. 60 0 c. 90 0 d. 120 0 13 of 13 10/16/2011 9:31 AM