Basic Electronics Objective Type Questions

BASIC ELECTRONICS OBJECTIVE TYPE QUESTIONSUNIT 1: SEMICONDUCTOR DIODES & APPLICATIONS 1.] Flow of electrons is generally termed as _____________. a) electric current b) electric shock c) semiconductor d) none of the above 2.] A _______________ is a material which offers very little resistance to the flow of current through it. a) good conductor b) insulator c) semiconductor d) none of the above 3.] The resistance offered by ______________ is extremely large for the flow of current through it. a) good conductor b) insulator c) semiconductor d) none of the above 4.] The materials which behave like perfect insulators at low temperatures & at higher temperatures, they behave like a good conductors are termed as ________. a) good conductor b) insulator c) semiconductor d) none of the above 5.] The conductivity of a semiconductor _____________ with temperature. a) increases b) decreases c) can’t say d) none of the above 6.] The conductivity of a good conductor _____________ with temperature. a) increases b) decreases c) can’t say d) none of the above 7.] The resistance of a semiconductor _____________ with temperature. a) increases b) decreases c) can’t say d) none of the above 8.] The resistance of a good conductor _____________ with temperature. a) increases b) decreases c) can’t say d) none of the above 9.] The charge of an electron is ___________________. a) 1.602*10+27 Coulomb b) 1.602*10-27 Coulomb +19 c) 1.602*10 Coulomb d) 1.602*10-19 Coulomb 10.] The total number of electrons in an atom depends upon ____________. a) the atomic mass b) the atomic weight c) the atomic number d) the atomic size MAHESH PRASANNA K., ECE, AIET Page 1 a) 4 b) 8 c) 10 d) 12 12. a) valence electrons b) free electrons c) can’t say d) none of the above 14. are termed as __________________.] In a semiconductor ___________. the outermost orbit is called ______________. a) valence band b) energy band c) conduction band d) forbidden band 19.BASIC ELECTRONICS 11.] The range of energies possessed by the free electrons is termed as ______. a) valence electrons b) free electrons c) can’t say d) none of the above 17.] In any atom. and no electron can exist in this void is termed as ______________. a) valence band b) energy band c) conduction band d) forbidden band 18.] In an insulator .] The electrons present in the valence orbit are termed as _______________.] The void (or gap) separating conduction band and valence band. a) valence band b) energy band c) conduction band d) forbidden band 15. AIET Page 2 . the number of electrons in the last orbit (i.e.] The energy band in relation to valence electrons is termed as ___________. the number of valence electrons is ___________. which are freely available for conduction.. a) less than 4 b) equal to 4 c) greater than 4 d) equal to 8 20. a) less than 4 b) equal to 4 MAHESH PRASANNA K. the number of valence electrons is b) equal to 4 d) equal to 8 21.] Electrons which are removed from the valence orbits of atoms.] The range of energies possessed by the electrons of any one orbit of all atoms is referred as _____________________. ECE. a) valence band b) energy band c) conduction band d) forbidden band 16.] In any atom. a) less than 4 c) greater than 4 material. the number of valence electrons is ___________. the outermost orbit or the valence orbit) is limited to ________________. a) valence orbit b) energy band c) conduction band d) forbidden band 13.] In a metal.. added to pure germanium material is termed as ____________.] A semiconductor in its pure form is termed as __________________. a _____________________ results.] In a n-type semiconductor material electrons are ________________. a) intrinsic semiconductor b) extrinsic semiconductor c) p-type semiconductor d) n-type semiconductor 24. like arsenic. a) dancing b) doping c) creating holes d) creating electrons 25.] The process of adding impurity to a pure semiconductor material.] If a trivalent impurity like gallium or indium or aluminium is added to pure germanium or silicon. a) intrinsic semiconductor b) extrinsic semiconductor c) p-type semiconductor d) n-type semiconductor 26.] The current which results in a semiconductor material due to the movement of holes is termed as ___________________. a) majority charge carriers b) minority charge carriers c) donor atoms d) acceptor atoms 29.. a) hole current b) electron current c) negative current d) none of the above 23.] A semiconductor to which an impurity is added with view to increase its conductivity is termed as __________________.] In a p-type semiconductor material holes are ________________. a) majority charge carriers b) minority charge carriers c) donor atoms d) acceptor atoms 28. in order to increase its conductivity is called as __________________. ECE. a) majority charge carriers b) minority charge carriers c) donor atoms d) acceptor atoms 30.] If a pentavalent impurity like arsenic or antimony or phosphorus is added to pure germanium or silicon.] The pentavalent impurity atom. AIET Page 3 . a) intrinsic semiconductor b) extrinsic semiconductor c) p-type semiconductor d) n-type semiconductor 27. a _____________________ results. a) majority charge carriers b) minority charge carriers c) donor atoms d) acceptor atoms MAHESH PRASANNA K.] In a n-type semiconductor material holes are ________________. a) intrinsic semiconductor b) extrinsic semiconductor c) p-type semiconductor d) n-type semiconductor 31.BASIC ELECTRONICS c) greater than 4 d) equal to 8 22. 5V 41. a) exactly in the middle b) at the lower part c) at the upper part d) none of the above 38. added to pure germanium material is termed as ____________. a) electrons only b) holes only c) both electrons and holes d) neither electrons nor holes 35. a) barrier potential b) developed potential c) p-n potential d) none of the above 39.] The trivalent impurity atom. the potential built across the junction.3V c) 0. a) majority charge carriers b) minority charge carriers c) donor atoms d) acceptor atoms 34. a) raises the Fermi level b) lowers the Fermi level c) do not affect the Fermi level d) none of the above atom 36. a) majority charge carriers b) minority charge carriers c) donor atoms d) acceptor atoms 33. the Fermi level lies _____________ of the forbidden energy gap. is termed as _______________.] Doping an intrinsic semiconductor with trivalent impurity atom __________. AIET Page 4 . like gallium. a) raises the Fermi level b) lowers the Fermi level c) do not affect the Fermi level d) none of the above 37. ECE.3V c) 0. the pn junction is said to be ______________.7V d) 1..1V b) 0.] In a p-type semiconductor material electrons are ________________.1V b) 0.] If an external voltage is applied across the p-n junction such that it neutralizes the barrier potential and causes conduction through the junction. conduction of current is due to ____________.] Doping an intrinsic semiconductor with pentavalent impurity __________________. a) forward biased b) reverse biased c) un-biased d) no-biased MAHESH PRASANNA K.] In extrinsic semiconductors.] In a pure semiconductor. after diffusion has stopped.5V 40. a) 0.] In a p-n junction.] The barrier potential is about ______________ of germanium. a) 0.BASIC ELECTRONICS 32.] The barrier potential is about ______________ of silicon.7V d) 1. ] The IRMS for a full-wave rectifier is _____________. ECE. a) same b) opposite c) can’t say d) none of the above 46. a) forward biased b) reverse biased c) un-biased d) no-biased 44..BASIC ELECTRONICS 42.6% b) 81.483% d) 1. a) 40.] The efficiency of a full-wave rectifier is _____________. a) – 1/IL b) – 1/VL c) – 1/RL d) – 1/If 47.] If an external voltage is applied across the p-n junction such that the depletion layer widens and the barrier potential increases.] A p-n junction blocks conduction when it is ________________. a) forward biased b) reverse biased c) un-biased d) no-biased 43. a) Im/ b) Im/2 c) 2Im/ d) Im/2 49. the p-n junction is said to be ______________.] The slope of DC load line is _______________.21% MAHESH PRASANNA K. a) Im/ b) Im/2 c) 2Im/ d) Im/2 50.] The Iav for a full-wave rectifier is _____________.6% b) 81.2% c) 0.21% 52. a) 40. a) forward biased b) reverse biased c) un-biased d) no-biased 45. a) Im/ b) Im/2 c) 2Im/ d) Im/2 51.2% c) 0.] The Iav for a half-wave rectifier is _____________.] A p-n junction conducts when it is _________________.483% d) 1.] The efficiency of a half-wave rectifier is _____________.] The IRMS for a half-wave rectifier is ______________. a) Im/ b) Im/2 c) 2Im/ d) Im/2 48.] The direction of conventional current is always ____________ to the direction of drifting electrons. AIET Page 5 . 2 c) 0. a) 40. ECE.6 b) 81.] The switch off time of diodes is longer due to _______________.21 54.] The ripple factor of a half-wave rectifier is _____________.21 55.] The direction of arrow head placed on the emitter of a transistor represents ________________. a) 40.] A capacitor ___________ to pass through it.] An inductor ___________ to pass through it. a) unbiased b) forward biased c) reverse biased d) none of the above 5..] The reverse current which results in a transistor due to minority charge carriers across the collector-to-base junction is called as ________________. a) unbiased b) forward biased c) reverse biased d) none of the above 4. a) base current b) emitter current MAHESH PRASANNA K. the emitter diode is ______________.483 d) 1.] During normal working of transistor as amplifier.] The ripple factor of a full-wave rectifier is _____________. the collector diode is ______________.2 c) 0. a) the direction of motion of holes b) the direction of motion of electrons c) both (a) and (b) d) none of the above 2. a) the diffusion capacitance b) the forward bias c) the reverse bias d) none of the above UNIT 2 & 3: TRANSISTORS & BIASING METHODS 1. a) allows DC b) blocks DC c) allows AC d) blocks AC 56.483 d) 1.] During normal working of transistor as amplifier.BASIC ELECTRONICS 53.] The direction of flow of electrons is ____________ to the direction of motion of holes. a) allows DC b) blocks DC c) allows AC d) blocks AC 57. AIET Page 6 . a) same as b) opposite c) parallel d) perpendicular 3.6 b) 81. ] a) α c) γ The ratio of change in emitter current to the change in base is ___________. the emitter-base & collector-base junctions are _________________ biased.] In the cut-off region. a) one b) two c) three d) four 7.] Varying the output current by varying the output voltage at constant input current is _____________________. a) forward b) reverse c) unbiased d) none of these 14. AIET Page 7 .] A transistor can be visualized as a ___________ port network. a) static input characteristics b) static output characteristics c) transistor i/o characteristics d) none of the above 8.. ECE. a) common base b) common emitter c) common collector d) none of the above 13.] Varying the input current by varying the input voltage at constant output voltage is _____________________. a) α b) β c) γ d) π 10.] The intersection of DC load line and the output characteristics of a transistor is called _____________________. b) β d) π 12. a) forward b) reverse c) unbiased d) none of these 15.] In the saturation region.] A ______________ circuit has a very high input resistance and very low output resistance.BASIC ELECTRONICS c) collector current d) collector-to-base leakage current 6.] The ratio of change in collector current to the change in emitter current at constant collector to base voltage is ___________.] The ratio of change in collector current to the change in base current at constant collector to emitter voltage is ___________. the emitter-base & collector-base junctions are _________________ biased. a) Q – Point b) quiescent Point MAHESH PRASANNA K. a) α b) β c) γ d) π 11. a) static input characteristics b) static output characteristics c) transistor i/o characteristics d) none of the above 9. a) emitter b) base c) collector d) none of these 24. a) 40 b) 30 c) 20 d) 10 21.] The collector-to-base bias circuit is also known as _______________. ECE.] The reverse saturation current doubles for every _________ temperature.] γ is the ratio of change in __________ current to the change in base current.] ICBO doubles for every _________ 0C rise in temperature.] The biasing circuit which gives most stable operating point is _________.] The stability factor ‘S’ is the rate change of _____________ current with respect to reverse saturation current. a) 40 b) 30 c) 20 d) 10 19. AIET Page 8 . a) emitter b) base c) collector d) none of these 25.BASIC ELECTRONICS c) operating Point d) all of these 16.] ICBO __________ for every 100C rise in temperature. a) base bias b) collector-to-base bias c) voltage-divider bias d) none of these 17.] β is the ratio of change in __________ current to the change in base current at constant collector to emitter voltage.] The reverse temperature.] α is the ratio of change in __________ current to the change in emitter current at constant collector to base voltage. a) emitter b) base c) collector d) none of these 23. a) doubles b) triples c) quadruples d) none of these 22. a) doubles c) quadruples saturation current __________ for every 0 C rise in 10 0C rise in b) triples d) none of these 20. a) base bias b) voltage-divider bias c) voltage feedback bias circuit d) none of these 18. a) emitter b) base c) collector d) none of these MAHESH PRASANNA K.. the emitter area is _________ doped. the collector area is _________ doped.] The emitter area in a transistor is considerably __________ than the collector area.] γ is the ratio of change in emitter current to the change in _________ current. a) smaller b) greater c) smaller or greater d) none of these 30. the depletion layer penetrates deeply into the __________ region. a) emitter b) base c) collector d) none of these 27.. AIET Page 9 .] β is the ratio of change in collector current to the change in _________ current at constant collector to emitter voltage.] α is the ratio of change in collector current to the change in _________ current at constant collector to base voltage. a) base b) emitter c) collector d) none of these 36. a) emitter b) base c) collector d) none of these 28. the current is mainly due to electrons. a) emitter b) base c) collector d) none of these 29. a) heavily b) lightly c) moderately d) none of these 34.] In a transistor. a) more b) less c) more or less d) none of these 32.] The depletion layer width at the collector junction is _________ than the depletion layer width at the emitter junction.] In a transistor. a) heavily b) lightly c) moderately d) none of these 35.] In a transistor. the base region is _________ doped. MAHESH PRASANNA K. a) heavily b) lightly c) moderately d) none of these 33.] In a ______________.] In a transistor. a) more b) less c) more or less d) none of these 31.BASIC ELECTRONICS 26.] The collector area is slightly _________ doped than the emitter. ECE. a) class A b) class B c) class C d) class AB 4. the collector current flows for less than half of the period of the input signal.] The collector-to-base bias provides __________ stability than the base bias circuit. a) early effect b) base width modulation c) (a) or (b) d) none of these 39. the collector current flows only during the positive half cycles of the input signal. a) PNP transistor b) NPN transistor c) BJT transistor d) UJT transistor 38. AIET Page 10 . the width of the depletion region also increases. the current is mainly due to holes. the collector current flows throughout the input signal cycle.] In CB configuration. a) class A b) class B c) class C d) class AB 3. a) least b) greatest c) more or less d) none of these UNIT 5: AMPLIFIERS & OSCILLATORS 1.] The voltage divider bias provides the _______ stability against hFE variations. when reverse bias voltage VCB increases above the VCB max.] In a _________ amplifier.] Audio amplifiers can amplify signals of frequencies which lie in the range of _____________. MAHESH PRASANNA K.] In a ______________.] In a __________ amplifier. which reduces the electrical base width.] In a ____________ amplifier.. This condition is called _______. increase in depletion region is such that it penetrates into base until it makes contact with emitter-base depletion region. a) punch-through effect b) reach-through effect c) (a) or (b) d) none of these 40.] In CB configuration. a) more b) less c) more or less d) none of these 41. ECE. when reverse bias voltage VCB increases. This effect is called as _________________.BASIC ELECTRONICS a) PNP transistor c) BJT transistor b) NPN transistor d) UJT transistor 37. a) 20Hz to 20KHz b) 20Hz to 20MHz c) 20Hz to 200KHz d) 20Hz to 200MHz 2. a) positive feedback b) negative feedback c) no feedback d) none of these 11. CC. a) positive feedback b) negative feedback c) no feedback d) none of these 12. there is a phase shift of _________ between input and output voltages.BASIC ELECTRONICS a) class A c) class C b) class B d) class AB 5.] R-C oscillators are usually used in ___________ range. a) 900 b) 1800 c) 3600 d) 00 10.] Tank circuit comprises of _____________.] The range of frequencies in which the amplifier gain is either equal to greater than 70.] When the phase of the feedback signal is out of phase with that of the input. a) an inductor in parallel with a capacitor b) an inductor in series with a capacitor c) an inductor in parallel with a resistor d) an inductor in series with a resistor 13. the collector current flows for more than half of the input signal period. a) channel-width b) frequency-width c) band-width d) none of these 8. but not throughout the full cycle.] In a ____________ amplifier.7% of the maximum gain is called as _______________.] The range of frequencies at the limits of which.] The coupling capacitor.. the voltage gain falls by 3dB is called as _______________.] In a common-emitter amplifier. a) channel-width b) frequency-width c) band-width d) none of these 9. then it is called ______________. AIET Page 11 . a) bypass the output to ground b) couple the output to next stage c) bypass the emitter current d) couple the emitter current to next stage 7. a) audio frequency b) radio frequency c) video frequency d) ultra high frequency MAHESH PRASANNA K. in a R-C coupled amplifier is used to _________. a) class A b) class B c) class C d) class AB 6. then it is called ______________. ECE.] When the phase of the feedback signal is same as that of the input. ] The bandwidth of an ideal Op-Amp is _____________.] The output impedance of an ideal Op-Amp is _____________.. the output is ____________. the inputs and outputs can take only two values. a) infinity b) zero MAHESH PRASANNA K.] The input impedance of an ideal Op-Amp is _____________. a) digital ICs b) linear ICs c) both (a) and (b) d) neither (a) nor (b) 4. a) an active element b) a passive element c) both (a) and (b) d) neither (a) nor (b) 3. ECE.] The voltage gain of an ideal Op-Amp is _____________.] The characteristics of ______________ changes with application of external voltage.] When equal voltages are applied to two input terminals of an ideal Op-Amp. a) infinity b) zero c) very high d) very low 7. AIET Page 12 .] The characteristics of ______________ will not change on application of external voltage.BASIC ELECTRONICS UNIT 6: OPERATIONAL AMPLIFIERS 1. 0 and 1. a) an active element b) a passive element c) both (a) and (b) d) neither (a) nor (b) 2. a) digital ICs b) linear ICs c) both (a) and (b) d) neither (a) nor (b) 5.] In a _____________. the outputs are proportional to inputs. a) infinity b) zero c) very high d) very low 6. a) infinity b) zero c) very high d) very low 8.] In _____________. a) infinity b) zero c) very high d) very low 9. ] The maximum rate at which the Op-Amp output can change is ___________.] The DC voltage which makes the output off-set voltage zero.] The input impedance of a practical Op-Amp is _____________. a) PSRR b) input off-set current c) output off-set current d) CMRR 15. ECE. a) output off-set current b) output off-set voltage c) input off-set current d) input off-set voltage 16. a) infinity b) zero c) very high d) very low 13. a) run rate b) ratio rate c) slew rate d) none of these 18. a) infinity b) zero c) very high d) very low 11.] Slew rate is expressed in terms of ______________. the output is ____________. This is called _____________. a) infinity b) zero c) very high d) very low 12. when the other terminal is zero is called _____________. AIET Page 13 . MAHESH PRASANNA K..] The voltage gain of a practical Op-Amp is _____________.] In a practical Op-Amp.] When equal voltages are applied to two input terminals of a practical OpAmp. a) output off-set current b) output off-set voltage c) input off-set current d) input off-set voltage 17.] The output impedance of a practical Op-Amp is _____________. there will be a small output voltage even when the inputs are zero.] The ratio of the differential gain of an Op-Amp to its common mode gain is ______________. a) infinity c) very high b) zero d) very low 14.BASIC ELECTRONICS c) very high d) very low 10. ] When the input is applied to the non-inverting input terminal of an Op-Amp. a) Vc/Vm b) Vc * Vm c) Vm + Vc d) Vm/Vc MAHESH PRASANNA K. a) 900 out of phase b) 1800 out of phase c) 3600 out of phase d) in phase UNIT 7: COMMUNICATION SYSTEMS & NUMBER SYSTEMS 1.] The time period for which the trace remains on a fluorescent screen after the applied signal becomes zero is known as ____________. a) the saw-tooth voltage b) the square wave c) the DC voltage d) the AC voltage 21.] If the frequency of the carrier wave is altered in accordance with the strength of the modulating signal. then the output is ______________ with the input.BASIC ELECTRONICS a) volts/µs c) µs/volts b) volts-µs d) µs-volts 19. a) modulation b) re-modulation c) demodulation d) none of these 4.] The modulation index ‘m’ for amplitude modulation is _____________.. then the output is ______________ with the input.] The time-base generator in a CRO is used to generate _______________. AIET Page 14 . then it is _________________. a) existence b) shadow c) persistence d) trace 20. then it is _________________.] The process of getting back the modulating signal from the modulated wave is _________________. a) amplitude modulation b) frequency modulation c) amplitude communication d) frequency communication 2. a) 900 out of phase b) 1800 out of phase c) 3600 out of phase d) in phase 22.] When the input is applied to the inverting input terminal of an Op-Amp.] If the amplitude of the carrier wave is altered in accordance with the strength of the modulating signal. a) amplitude modulation b) frequency modulation c) amplitude communication d) frequency communication 3. ECE. the intermediate frequency is _______________. a) 15 b) 16 c) 18 d) 14 10. then a) X = 27 c) X = 17 b) X = 37 d) X = 12 11.] If 5810 = XBCD. then a) X = AB c) X = EF 16.] Usually. a) 3311(8) b) 3113(8) c) 1133(8) d) 1331(8) 15. a) 455 MHz b) 455 KHz c) 455 Hz d) 455 GHz 9.] If 4710 = X8. ECE. a) f/fm b) f * fm c) f . AIET Page 15 .BASIC ELECTRONICS 5.fm d) fm/f 6.] The 1’s compliment of 1110 is __________. a) 1111 b) 0001 c) 0010 c) 0000 12.] The modulation index ‘mf’ for frequency modulation is _____________. a) 1111 b) 0001 c) 0010 d) 0000 13.] 110112 = X10.. then a) X = 01011000 c) X = 10101000 b) X = CD d) X = DE b) X = 01010001 c) 10100001 MAHESH PRASANNA K.] If 110211102 = X16. then a) X = 37 b) X = 27 c) X = 74 d) X = 57 14.] The 2’s compliment of 1110 is ____________.] The decimal equivalent of binary number 1110 is ________________.] The octal equivalent of 001001011011 (2) is _________________. a) boolean addition b) boolean multiplication c) Boolean subtraction d) boolean division 2. AIET Page 16 . a) low b) high c) low or high d) none of these 5.] The output of a NOR gate is ___________.] A bubbled OR gate and a _____________ are equivalent. a) boolean addition b) boolean multiplication c) Boolean subtraction d) boolean division 3.] The AND operation implies ______________. of E & C. when all the inputs are high.BASIC ELECTRONICS UNIT 8: DIGITAL ELECTRONICS 1. a) low b) high c) low or high d) none of these 4. a) XOR gate b) XNOR gate c) NOR gate d) NAND gate 6. AIET.. ECE. MAHESH PRASANNA K.. Dept. when all the inputs are low. a) XOR gate b) XNOR gate c) NOR gate d) NAND gate ____________***____________ By – MAHESH PRASANNA K.] A bubbled AND gate and a _____________ are equivalent.] The OR operation implies ______________.] The output of a NAND gate is ___________.