PROTECTION AND SWITCHGEARMULTIPLE CHOICE QUESTIONS 1) A 3φ line delivers 3600 kW at a p.f. 0.8 lagging to a load. If the line voltage at receiving end is 32 kV, determine line current. A. 0.812 A B. 8.12 A C. 81.2 A D. zero 2) Which braking is not possible in series motor? A. Regenerative braking B. Dynamic braking C. Rheostatic braking D. Counter current braking 3) Polarity of supply voltage is reversed in which type of braking? A. regenerative braking B. plugging C. dynamic braking D. none of these 4) A consumer consumes 600kWh per day at a load factor of 0.40 if the consumer the load factor of 0.70 without increases the maximum demand what is the consumpation of energy in kWh? A. 2770 kWh B. 1260kWh C. 1050kWh D. 2500 kWh 5) In which braking back emf exceeds supply voltage? A. dynamic B. regenrative C. Plugging D. none of these 6) What type electric drive is used in cranes? A. multimotor B. group C. individual D. both A and C 7) The full form of VVVF control A. variable voltage VAR frequency B. VAR variable voltage frequency C. variable VAR voltage frequency D. variable voltage variable frequency 8) Pf can be improved by using A. series capacitor B. capacitor and resistor in series C. indictor and capacitor in parallel D. only shunt capacitor 9) Which of the following is not base load power plant? A. pump storage B. run water C. diesel D. nuclear 10) The bridge used for measurement of insulation cables? A. wien B. maxwell C. schering D. Kelvin 11) For a fixes value of complex power flow in a transmission line having a sending end voltage V, REAL POWER LOSS will be proportional to A. V B. 1/V 22 C. 1/V D. V 22 12) the sequence components of the fault current are as follows : IPOSITIVE = j1.5PU, I NEGATIVE = -j0.5pu , I ZERO = -j 1pu . Which fault is this A. LLG B. LG C. LL D. LLLG 13) Q meter works on principle of A. mutual inductance B. series resonance C. self inductance D. parallel resonance 14) The conduction loss versus device current characteristics of a power MOSFET is best suited by A. parabola B. straight line C. rectangular hyperbola D. exponentially decaying function 15) The positive reactance equals to negative sequence reactance if equipment is A. motor B. transformer and transmission line C. generator D. all of these 16. Number of sign changes in the entries in 1st column of routh array denotes the no. of A. roots of characteristic polynomial in RHP B. zeroes of system in RHP C. open loop poles in RHP D. open loop zeroes in RHP 17) C eq of two capacitors connected in series is given by A. C1C2 B. C1=C2 C. C1C2/C1+C2 D. C1+C2 18) What is maximum value of a load which consume 500 KWh per day at a load factor of 0.40 if the consumer increases the load factor of 0.50 without increasing the maximum demand? A. 60 kW B. 23 kW C. 40.5kW D. 52.08 kW 19) If length of capacitor is doubled its capacitor is C. busbars 25) An electric current of 6 A is same as A. 2. 6 watt/second D. fuses D. relays and CB 24) MERZE PRICE current scheme protection is used in A. alternator C. both a and b D. 3 core cable C. inversely proportional C. then the dielectric strength of insulation should be A. switches C. D. all of these B. transformer B. both D. none of these 2 1) If cable of homogenous insulation has maximum stress of 5KV/mm . no effect D.5KV/mm B. 2 C. 3 single core cable B. 6 joule/second B. white. yellow and oranged red B. black C. outdoor D. no change 20) For voltage level beyond 66KV . 26) Majority of distribution substations are of what type A. halved B. 6 Coulomb/second. doubled C. 5KV/mm 22) There are how many types of dc distributors A. 3 B. 25kv/mm C. quadrupled D. none of the above. underground 27) Effect of temperature on internal resistance of a battery A. 3 phase system employs A. both b and c . indoor C. pole mounted B. 0KV/mm D.A. directly proportional B. 5 D. 4 23) switchgear equipments include A. none of these 28) What are the various colours obtained in cold cathode tubes A. Which lamp has the more resistance A. vacuum B. dc system B. wooden D. every 12 months D. board of thermal unit C. oil impregnated paper C. electron chemical equivalent C. glass 30) What traction system is used for suburban and urban services A. dry wooden B. none 3 1) Recommended preventive maintenance inspection time of bushings of transformer A.U stands for A. stainless steel C. painful shock but no muscle contraction D.O. not connected at all D.29) What dielectric material are used in the capacitor used for pf correction A. 40W 36) Capacitor banks are connected with ac induction motor A. board of trade unit 35) There are 3 lamps of wattage 40W. mica D. electrolysis cathode equivalent 38) field winding is in series with armature winding in . ALL of their resistance are same B.T. 60W D. severe burns and death 33) What type of ladder is used for overhead lines work A.80W respectively . muscles contractions and breathing will be affected C. in series C. every 6 months B. ac system C. 80W C.C. british thermal unit B. electro chemical equivalent D. time of overhaul 32) 20mA – 40mA current flow through human body may cause A.60W. can be connected either way –series/parallel 37) E. electrovalent chemical equivalent B.E stands for A. british oxygen trade unit D. aluminium 34 ) B. every 18 months C. either ac/dc D. mild sensation B. in parallel B. voltage drops are according to their resistive value 40) Capacitor fitted with ceiling /table fans is of the value of A. 5-10 farad 4 1) factors on which speed of dc motor depends upon A. all of the below B.62 D. MHCP/MSCP C.62X10-03 45) To a highly inductive circuit . indeterminant 46) Value of current at resonance in a series RLC circuit is affected by the value of A. capacitor start B. dc shunt motor B. L B. shaded pole 43 ) redu tion factor f in illumination is A. 1/MHCP D. dc series motor C. The angle between voltage and current will A. a small capacitance is added in series . remain same D. 15 B. 1-2 microfarads B. capacitor run C. NONE 47) How does the depth of laying affect the current carrying capacity of cables A. armature current 42) which 1 phase motor does operate at high p. 0. R D. heat losses in both are same D. increase C. dc compound motor D.decrease B. decreases B.load factor= A. 1/15 C. currents in both are same C. 2-3 microfarad C. field flux D. 0.1 microfarads D.A. increases . 0. applied voltage C. 1/MSCP 44) Maximum demand of consumer is 80kw and his daily energy consumption is 1200 units . voltage drops across both are same B. both a and b 39) A circuit contains two un equal resistor in parallel A.f A. split phase D. C C. MSCP/MHCP B. cable 53) What gases are used for TIG welding A. 34 D. 1.0 m B. conductor D. argon B. 2. 3 B. nitrogen D. 2 D. moulded case circuit breaker B.0 m 49) Function of bituminous compound in joints of cable is A. 57) In speed time curve of train what stage comes after free running . 2000 52) Insulated conductor is termed as cable A.C. 1. provide mechanical strength D. total flux in lumen / 4 &pi 51) Melting point of of tungsten filament indegree centigrade is A. 0. wire B. lumens/watt C.C.C. minimum case circuit breaker D.5 m D.B is A. what minimum horizontal and vertical clearance there should be for the separation between these 2 cables? A. total flux in lumen / 2 &pi B. 4 56) In dc series motor torque is A. miniature case circuit breaker C.6 m C. all 54) Full form of M. unchanged D. pipe C. no relation with current. minimum contact circuit breaker 55) Meggar has how many terminals A. 340 C. 3400 B. 1 C. protect joints from moisture penetration C. doubles 48) When power cables are laid in proximity of communication cables . none of these 50) In illumination what is lamp efficiency A. helium C. proportional to the current B. Protect joints from heat B. lumen-watt D. inversely proportional to current’s square D. proportional to the square of the current C. underground C. 1 &phi is used for supplying power to the locomotives throughout India except which zone A. none 63) Piezoelectric effect is carried out in A. m derived D.A. synchronous speed D. urban B. initial acceleration C. large plant 67) precommissioning tests to be carried out on transformer . north D. east C. small plant B. Cshunt 65) property of pure inductor is A. south 60) BELL transformer is A. only stores energy B. independent of any factors 62) Length of sections in overload supply system depends on factors A. pole and rotor speed C. crystal filter C. rural 59) 25kv. substation spacing B. constant speed D. no.50hz . of poles and synchronous speed B. step down C. both D. constant k prototype 64) In Cauer 1 form last element in the network is A. coasting B. Lseries B. donot dissipate energy but only stores it 66) hydrogen cooling is used in A. step up B. Lshunt D. misnomer not a transformer 61) factors on which frequency of alternator depends A. 1:1 D. composite filter B. traffic density C. both D. medium plant C. west B. suburban D. Cseries C. braking 58) METADYNE control method is employed in which traction system A. dissipated energy and also stores it D. donot dissipate energy and donot store also C. 1/5 times the synchronous speed D. 5 times the synchronous speed B. 500 W . 10111 D. 1/15 times the synchronous speed C. dc power transmission line B. electrical menu unit B. 24000kwh D. gas welding D. electrical multiple unit C. vector group tests D. none 74) 1s complment of 17 is A. gap increases arrestor will not work B. 240kwh 69) Peterson coil is used in A. 1000 W D. both a and b 70) Effect of gap between horns in horn gap arrestor A. gap decreases arrestor will not work C.What will be capacity of the heater if the length of the wire is halved A. relay trip tune D.T stands for A.A. electric arc welding 72) R. arc welding B.5 times the synchronous speed 76) A 1000 watt heater has a wire length of 5 Meters. 0. relay tripping target 73) EMU stands for A. ratio test C. 11100 75) The speed of rotation of 5th harmonic component in the stator of an induction motor is A. dc motor D. polarity tests 68) How much KWh energy is produced by fission of 1gm of uranium U235 A. resistance welding C. 3000 W C. none 71) alternating current is found most suitable for A. 10001 C. 24kwh B. 2000 W B. round trip time B. all of the options B. gap increases arrestor will work better D. relay trip time C. ac transmission line C. electrical manual unit D. 2400kwh C. 01110 B.T. Assume supply frequency to be 50 Hz. 74. B. . 750.56% B. 8 1) Where is metadyne control employed:A. 78.33% C. reversing switch 84) What will be the total flux emitted by a source of 60 candle power A. resistance C. D. choke D. pizoelectric B. Three phase induction motor.5µF . Underground railway. copper D. 745.2 Lumens 85) Which one of the following is a passive transducer:A.2 Lumens D. photovoltaic cell D. improve power level D. 80. Urban railway C.77) What will be its capacity when the distance between two plates of a condenser of capacity 8µF in reduced from 10 mm to 4 mm:A. 764. C. 78) Why are capacitors used with large a. Tantalum B. induction motorA. 10µF. B. 5µF. 20µF. Tungsten 83) Which is connected in parallel with the starter of a flurocent tubeA.25% 80) Which motors not used for sub-urban services A. Improve voltage level. D. Improve current level 79) What will be the thermal efficiency of a 240 V . C.45 Lumens B. Sub-urban railway B. Dc shunt motor. Condenser B. Carbon C. 780.c. 82) Which metarial is mostly used for the filament of incandescent lampsA. Improve power factor C. Main line service railway D. B.45 Lumens C. LVDT. 86) Calculate the reactance of Peterson coil suitable for a 33KV . 30µF. AC single phase series motor. C. 79.1000W electric Kettle if it brings 2 Litres of water at 15 Degree C to boiling point 15 Minutes A. Ordinary Dc series motor.96% D.3phase transmission line having capacitance to earth of each conductor as 4. Thermocouple. 8mm . 89) If L&C are 4mH&0. 240.The wire blows off at a current of 8 Amp. 25060 J D. C. npne of these 88) A fuse wire of circular cross-section has a radius of 0. 10 D.2 Amp at 120 V .0001µF respectively a current chop of magnitude 50 Amp would induced a voltage A. 8 C. 100 Kv C.8Ω B.How much energy is costper minute of operation:A.6 lagging . 40. 220Ω 87) Majority of distribution substations are of which type:A. indoor B.f. 4 mm. outdoor D. 7 92) Mechanical energy is supplied to a dc generator at the rate of 4200J/S .Determine the overall efficiency:A. B.28 Kg per Kwh . 30.4 mm. of 0.000Kcal/kg.4Ω C.7%.Calculate the radius of wire that will blow off at a current of 1 amp:A. D. 200 Kv B. 250 Amp B. 30. 100 Kw C.If the power factor is raised to unity . 0. 350 Amp. 9 1) What is the value of safety factor of pin type insulator A. 235.The generator delivers 32. 20160 J C.How many more kilowatts can alternator supply for the same KVA loading :A. . 200 Amp D. 50 Kv D.26%. 2 mm. 300 Amp C. 500 Kw B. 23060 J 93) A dissel power station has fuel consumption of 0. 0. 230Ω D. C. B. 300 kw D. 94) An alternator is supplying a load of 300Kw of a p.A.The calorific value of fuel being 10. 200 Kw.the shortcircuit current will beA. 12 B. polemounted C.85%. D. 400 Kv 90) If the percentage reactance of an element is 20% & the fullload current is 50 Amp. 20060 J B.2 mm. 40%. 7 ohms D. both wiring&winding wires C. 750 Kgs C. nickel D.5 Kg/m &working tension is 1500 Kg. C.Determine clearance from road level:A. 32.95) An overhead line crossing a road supported by two towers of 50m& 70m from road level with span 250 m.8 m. Reciprocal of the load factor C. 46. Electrical Motors Unit.7 ohms 99) Where is annealed copper conductor usedA. volt ampere C. 8. volt/ampere B. B. busbars 100) What is the full form of EMU A. cables D. 7. 98) If the three colour bands of a resistor are grey. 96) What is the coincidence factor? A. Electro Motors Unit. 1000 Kgs B. 48. 9. D. 62. C.5%. 65%. B. 101) What materials are used for overhead trolley wire:A. Electrical Multiple Unit.3 m. 1022 Kgs 103) Which of the following is not the unit of electrical power A. D. Electro Motive Unit.9 m. D. watt D. Reciprocal of the plant factor D.7 ohms B. joule/second . Bronze C.7 ohms C. C. 6. Copper Alloys. violet & gold. What is his loadfactor A. 102) How would you determine the weight of counter weight of a Lift (weight of griddle with cage may be taken 3⁄4 ton) A. 28. Reciprocal of the diversity factor B. overhead conductors B. B. None of these 97) The maximum demand of a consumer is 80 KW & his daily energy consumption is 1200 units. 272 Kgs D. 60%.9 m. what is the vaue of the resistor:A.The weight of conductor is 1. 70%. Aluminium B. earth pit D. Up to 66 Kv 105) Where is one & half breaker arrangement used:A. 667 A C. Then percentage slip at fullload isA. 333 A D. none of thes 112) Power system is protected from lightning by use of A.104) Where air circuit breakers are used:A. High voltage system B. What is the series resistance with source required:A. Maxwell D.6. 12. 109) The bridge used to measure insulation of cable isA. Kelvin 110) In an induction motor the ratio of starting current to fullload current is 12. 7. 111) In a synchronous motor . 6.67KA 108) A uniform plane welectromagneic wave incident normally on a plane surface of dielectric is reflected.64% D.2 Ohm D.38 Ohm 107) A surge of 300 Kv travelling in a line of characteristic impedence 400 Ohm arrives a junction with two neutral impedences 600 Ohm & 300 Ohm. C. lightning arrestor B. 6. 0. 1% B. Schering C.65 & the ratio of starting torque to fullload torque is 1. Wien B. B. Up to 33 Kv C. Armature curret & Power factor C.the inverted curve represent the relation betweenA.45 Ohm B. Up to 12 Kv D.2 A. earth riser 113) When a neutral point of 3 φ system is directly connected to earth then it has what type of grounding . earthing mat C. Medium voltage system D. Field current & Armature current B. 50%. 10%.01% C. 6 Ohm C. 75%. The minimum voltage at input is 24 V.56%. 25%. Find the transmitted current in the 300 Ohm line. D. 5. Field current & Power factor D. 106) A zenner voltage regulator has load requirement of 12 V & 2 A. Upto 11 Kv B. 12. A. C. with V of 3 what is the percentage of incident power that is reflected:A. Extra high voltage system. None of the above. The zenner diode minimum current requirement is 0. 450 A B. cal/lt 116) Percentage of carbon is highest in A. flash over voltage /puncture strength C. diesel power C. steam power B. horngap B. Peterson coil 114) In substations most commonly used arrestor is A. demand factor C. C. UAE D. U. average demand B. solid B. diversity factor 122) Safety factor of insulator is A. ENGLAND 120) India's 1st nuclear plant was set up at A. horn gap B. rod gap C. lignite . rodgap D. nuclear D. Tarapur D. Rana pratap sagar C. cal/gm C.A C. expulsion type D. hydroelectric 118) What are the types of lightning arrestors A.S.S. load factor D. all of the above 119) The 1st nuclear plant in world was commissioned in A. D. puncture strength / string efficiency 123) What is the full form of MNP .R B. Bhaba 121) Maximum demand / Connected load = A.A.S. multigap 115) Calorific value of solid fuel is expressed as A. thyrite C. Kalpakkam B. reactance D. 117) Cheapest plant in operation and maintenance is A. resistance C. coal gas. U. puncture strength /flash over voltage B. anthracite coal B. bituminous coal. kcal/gm B. kcal/lt D. string efficiency/flashover D. None of these 130) A 200 km long 3φ transmission line having sending end voltage of 44 kV and current of 178 A. physical length of the line C wavelength of the line D. Magnetic neutral pole.f. vacuum B. A. 9.000315. D = 0. number of turns of restraining and operating coil D.992. 19. C = 0.The multiplying power of 100 ohm shunt with this galvanometer is A. Calculate the load current. D. SF6 127) In a biased differential relay the bias is defined as the ratio of A. A = 1 + YZ/2 129) A 3φ 100 km long transmission line is supplied by load of 20 MW at 0. the following circuit breaker is suited for capacitor bank switching A. air blast D.0175 A. Magnetic field neutral pole. fault current and operating coil current B. oil C. Magnetic field neutral plane. medium and long line is primarily based on A. 11 B. if its sending end voltage is 82. lagging at 66 kV at receiving end. receiving end voltage is 76. power transmitted over the line 126) Keeping in view the cost and overall effectiveness. 100 C.5 A D. 7. 124) A galvanometer of full scale current of 10 mA has a resistance of 1000 ohm.25% D. 10.6 kV. 94% C. D = 1 + YZ/2 B. 96% D. B = 55. 195 A C.9 p. nominal voltage of the line B. 1. 110 D. 8. 98% 131) What is the % regulation of a balanced 3φ transmission line at no load. 10 125) The concept of an electrically short. A. C = 1 + YZ/2 C. fault current and restraining coil current 128) For a medium transmission line which one is true? A. 92% B.5. Given transmission line parameters are : A = 0. Magnetic neutral plane C.A. operating coil current and restraining coil current C.25% . B = 1 + YZ/2 D. B. If the line supplies load of 20 MW at 0.9 p. then determine the transmission efficiency.95 A B.2 kV.f.25% C.25% B. 72.2o B. A. D⃗ = 0. 2. ± 6% C.4 MW 137) A long transmission line has the following auxiliary constants: A = D = 0. C⃗ = 25.38X104 ∠90o mho.83 D. X = 97.5 C. C⃗ = 28. B⃗ = 3. Given. 23. B = 200∠75o Determine the power at unity power factor that can be received at if the voltage profile at each end is to be maintained at 275 kV.5∠3.4 Ω. 2725 MW D. A⃗ = 22. B⃗ = 0. ± 5% D.9o kV. Two similar transformers.835∠6.7.8 MW D.9o kA. 0. 3257 MW . ± 8% B.8 MW d) None of these 135) Find the load angle in the above question if power demanded by load is 150 MW A.85o D. 42. 0.3 MW b) 117.98∠2o. 75. C = 0. B⃗ = 0. What is the sending end power? A.64o C. 1835 MW C. 82. each of impedance 12∠80o Ω are interposed at the two ends of the above transmission line.9o A.958∠3.132) In nominal π method. 53.00282∠53o. A = 0. A⃗ = 45. R = 27. C⃗ = 29. C⃗ = 32. . Determine the values of Ao to represent the line with the transformer. find the sending end voltage. δ = 22o a) 215. 28.2o 138) As per IE rules th maximum allowable variation between declared and actual voltage at consumer premises should be A.2 MW C.385 B. Then SIL of compensated transmission line will be A.532∠52.23∠47.2∠0o. B⃗ = 2.9 MW B.69.85∠5o. 2280 MW B. 53. VR = 76.3X10-3∠-36.98o D.86o B.2. IR = 109.164∠-36. A⃗ = 42.53o B.5∠5. 0.1. A⃗ = 52. 82.2o 133) Which combination is true for any transmission line A. 52.8.5∠13o D. Y = 7. I S = 0.5∠56o C.5 Ω. 72. D⃗ = 0.7 MW c) 156.9o 136) For a 50 Hz 300 km long transmission line VS = 145∠4. ± 7% 139) A lossless transmission line having surge impedance loading (SIL) of 2280 MW is provided with a uniformly distributed series capacitive compensation of 30% . 43.81o C. B = 28∠69o. D⃗ = 0.68 134) A 275 kV transmission line has the following line constants. D⃗ = 0. have unity power factor D. none of these 147) In nominal T method A.4 km B. same as medium transmission line D.707 leading B. 0.24% C. The line constants are uniformly distributed over the entire length B.707 lagging C. have zero power factor 141) An extra high voltage transmission line of length 300 km can be approximated by a lossless line having propagation constant β=0.f lagging.9 kV D. Determine the sending end voltage.00127 radians per km. full charging current flows over half the line D. 24. so for line frequency 50 Hz. each section will have line constants n times of whole line . zero 144) The capacitance effects of short transmission line is A.05% 142) The electrical power transmitted by a line is at the speed of light. 12. A. then the load will be A. 0. 10000 km D. A. half charging current flows over half the line 148) Which statement is false for long transmission line? A.8 kV B. 8000 km B.140) If in a short transmission line.12% D. Then percentage ratio of the line length to wavelength will be given by A. high C. length of the line should be A. the voltage regulation is A. 100 km D. 37.f. Leakage susceptance and leakage conductance are shunt conductance are series elements C. The total resistance and inductive reactance of the line 10Ω and 15Ω respectively. positive B. 19. positive or negative D. same as long transmission line 145) A single phase overhead transmission line delivers 1100 kW at 33 kV at 0. Resistance and inductive reactance are the series elements D.8 lagging can be delivered by a 3-phase transmission line having conductors each of resistance 1Ω per kilometre. 16. 26. 7000 km C.06% B.2 km C. full charging current flows over full the line B.7 kV C. negligible B. 57. 6000 km 143) When the load power factor in a three phase short transmission line is leading. The voltage at the receiving end is to be 132 kV and the loss in the transmission is to be 5%. If a line is divided in n section. half charging current flows over the full the line C. negative C.8 p. 6. 33. None of these 146) Estimate the distance over which a load of 15000 kW at a p. resistance and reactance are found to be equal and regulation appears to be zero. 0. C= Z. If the loss of line is 15 MW and the load is 150 MVA. 220/√3 154) A single phase transmission line of impedance j0.6 lagging C. 220 A D. data insufficiency for decision 157) The conductor of a 10 km long.037. D constants: A = D = 0.96. 23. D=Z 150) An 11 kV. D=1 B. 0. 80. it is necessary for the sending end and receiving end to be operated in synchronism. Its charging current will be A.8 mH B. the inductance of the circuit is A. D=0 D.5 m.8 lagging power factor is supplied at 11 kV at the distant end. short line B. If the conductors are of copper. 152) A 100km long transmission line is loaded at 110 kV. C= Z. power transfer capability is limited by stability considerations. if dc voltage is supplied for the same set up. B = 25. the string efficiency will be A. A=1. unity B.8 ohm supplies a resistive load of 500A at 300V. . a) 24.88 % d) None of these 151) In a DC transmission line A.the resistance of the line is A. 3-phase transmission line has a resistance of 1.06 ohms per phase C.8 leading 155) For an existing ac transmission line. 11/√3 A B.149) Which combination is true for short lines A. Calculate the percentage regulation and efficiency of the line when a total load of 5000 kVA at 0. C. B=1. single phase. B=1. 20 km long. C=0.6 ohms per phase B. The diameter of each conductor is 1 cm. 100% B.806 ohms per phase D.0806 ohms per phase 153) A 220 kV. there are no effects due to inductive and capacitive reactances. medium line D. B. long line C. 0. D.5 Ω and reactance of 4 Ω per phase. 80% D. 3-phase transmission line has the following A. B=0.the string efficiency is 80%. the effects of inductive and capacitive reactances are greater than in an AC transmission line of the same rating. 45. A=0.3 mH . 0. C. 0. a 50 km long power line will be modelled as A. The sending end power factor is A. D=1 C. A=0.88 % b) 14. B=Z. 8. two wire line are separated by a distance of 1. A =1.88 % c) 34. B.8 leading D. <80% 156) For a 500 Hz frequency excitation. C=1. 0. 11 A C. C = 0. 90% C. 150 D.6-j0. 200 / √2 B. 20 C. 3-j4 mho 159) A 500 kVA 2300/230 V. 1 ohms 160) The illumination at a point 5 meters below a lamp in 6 lux. 100 V is conneted in series with another lamp Y of the same type nut rated 100 W. 8 163) in an induction relay for a particular current setting the operating time 4 sec. 220 / √2 C. 0. 65. The candle power of the lamp is A 30π B. 20 D.7 mH D.3 mH 158) A coil has an inductive reactance of 4 ohm and a resistance of 3 ohm the admittance of the coil is A. 150 D.0035 ohm the equivalent resistance of the machine referred to the secondary A. 0.8 if the time multiplier setting is rest to 1 the operating time is a) 5 b) un changed c) 10 d) 1 164) An RLC series circuit resonates at a frequency wr the ratio of wr L/R = 10 the variable frequency voltage applied to the circuit is 20 sin (ω t = π/3)the voltage measured across the capacitance A. 145 166) A metal filament lamp X rated 40 watts.01 ohms C. 75 B. 20 / √2 D. 60Hz single phase transformer has a high voltage winding resistance 0.8 mho D. 200 V A voltage of 200 V is applied across the combination then .65 ohm and a low voltage winding resistance of 0. 10 162) If the fault current is 2000 A.16 mho C. 200 161)A 400/200 V transformer has a pu impedance of 0.05 the HV side voltage required to circulate the full load current during short circuit test is A. 5 C. 375 C. the relay setting is 50% and CT ratio is 400/5 then the plug setting multiplier will be A.001 ohms D. when the time multiplier setting is 0. 50. 140 C.6535ohms B. 0. 3+j4 mho B. 0. 10 B.12 .i 0.C. ½ 165) A shunt generator has a critical filed resistance of 300 ohms at a speed of 800 rpm if the speed is raised to 1000 rpm the critical filed resistance is A. 225 B. 6 D. 0. 25 ohms and 5 ohms D. none of the lamp will glow 167) An ac voltage of 200 V at 50Hz is applied to a coil which draws 5 amp and dissipates 1000 W. 220km D. If the phase sequence is RYB the phase current IYB is A. 36 D.5 171) Upto what length of transmission line the capacitance can be neglected A. 30 C. 150km 172) Ferranti effect is seen in which transmission line A. the resistance and impedance of the coil respectively are A. 40 ohms and 40 ohms B. 20 170)The balanced short circuit current of a 3 phase alternator is 50 A at a speed of 1500 rpm for the same filed current the balanced short circuit current at 1200 rpm would be A. 75km C. ZERO P. all of the above 174) What are the methods for determining regulation of an alterntaor A. 40 ohms and 200 ohms C.F METHOD C. 55. lamp Y gives more light C. 10 D. 80 C. emergency plants D.1 B. 50 169) The line current IR flowing into balanced delta connected load is -j5√3 A. lamp X gives more light B. SYNCHRONOUS IMPEDANCE METHOD B. Both will be equally bright D.F METHOD D. peak load plant C. 24 D. short D. zinc sulphide+ manganese . 5 C. 40 B. 62.A. If an auto transformer with 60% tapping is used for starting the current drawn from the mains will be A. 18 B. medium C. ALL 175) Name of the fluorescent materials for fluorescence of green colour A. 50 ohms and 200 ohms 168) A 3phase inducation motor draws a current of 50 A from mains when starts by direct switching.M. both a & b 173) Uses of diesel power stations A. long transmission line B. zinc silicate + manganese B. M. standby plants B. 120km B. VL = 1/ √3 VP C.f. 100 KVAR D. Does not vary with power factor C. star B. split phase C. . VL = √3 VP D. capacitor run B. 200 B. increase in load p. FRLS D. LSOH 183) What is the flash point of transformer oil in degree centigrade A. mesh D. VL = VP B. weight of conductor B. tensile strength of conductor D. >300 184) For a 3φ transmission line transmission efficiency of a line decreases with A. none of these 181) Which 1 φ motor is used for refrigerator A. thermal B.C. XLPE C. increase in load current. calcium silicate + manganese 176) Example of base load stations are A. both a & b D. universal D. delta C. none of these 178) In what connection we get neutral A.f. both a & b 179) Sag depends upon A. none of these factors 180) What is the relation between line voltage & phase voltage in case of delta connection A. both a & c C. 80 KVAR C. zinc sulphide + silver D. hydro C. 140 D. gas turbine 177) What will be the reactive power in a circuit when the apparent power & actual power drawn by that circuit are 100 KVA & 60 KW A. MIND B. B. 80 C. repulsion 182) What type of cable are used in hill /mines A. 120 KVAR B. decrease in load p. D.
Report "Objective Question Protection and Switchgear"