BASIC ELECTRONICS OBJECTIVE TYPE QUESTIONS

UNIT 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) cant say d) none of the
above 6.] The conductivity of a good conductor _____________ with temperature. a) increases b)
decreases c) cant say d) none of the above 7.] The resistance of a semiconductor _____________ with
temperature. a) increases b) decreases c) cant say d) none of the above 8.] The resistance of a good
conductor _____________ with temperature. a) increases b) decreases c) cant 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

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11.] In any atom, the number of electrons in the last orbit (i.e., the outermost orbit or the valence orbit)
is limited to ________________. a) 4 b) 8 c) 10 d) 12 12.] In any atom, the outermost orbit is called
______________. a) valence orbit b) energy band c) conduction band d) forbidden band 13.] The
electrons present in the valence orbit are termed as _______________. a) valence electrons b) free
electrons c) cant say d) none of the above 14.] The range of energies possessed by the electrons of any
one orbit of all atoms is referred as _____________________. a) valence band b) energy band c)
conduction band d) forbidden band 15.] The energy band in relation to valence electrons is termed as
___________. a) valence band b) energy band c) conduction band d) forbidden band 16.] Electrons
which are removed from the valence orbits of atoms, which are freely available for conduction, are
termed as __________________. a) valence electrons b) free electrons c) cant say d) none of the above
17.] The range of energies possessed by the free electrons is termed as ______. a) valence band b)
energy band c) conduction band d) forbidden band 18.] The void (or gap) separating conduction band
and valence band, and no electron can exist in this void is termed as ______________. a) valence band
b) energy band c) conduction band d) forbidden band 19.] In a metal, the number of valence electrons is
___________. a) less than 4 b) equal to 4 c) greater than 4 d) equal to 8 20.] In a semiconductor
___________. a) less than 4 c) greater than 4 material, the number of valence electrons is

b) equal to 4 d) equal to 8

21.] In an insulator , the number of valence electrons is ___________. a) less than 4 b) equal to 4

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c) greater than 4 d) equal to 8

22.] The current which results in a semiconductor material due to the movement of holes is termed as
___________________. a) hole current b) electron current c) negative current d) none of the above 23.]
A semiconductor in its pure form is termed as __________________. a) intrinsic semiconductor b)
extrinsic semiconductor c) p-type semiconductor d) n-type semiconductor 24.] The process of adding
impurity to a pure semiconductor material, in order to increase its conductivity is called as
__________________. a) dancing b) doping c) creating holes d) creating electrons 25.] A semiconductor
to which an impurity is added with view to increase its conductivity is termed as __________________.
a) intrinsic semiconductor b) extrinsic semiconductor c) p-type semiconductor d) n-type semiconductor
26.] If a pentavalent impurity like arsenic or antimony or phosphorus is added to pure germanium or
silicon, a _____________________ results. a) intrinsic semiconductor b) extrinsic semiconductor c) p-
type semiconductor d) n-type semiconductor 27.] In a n-type semiconductor material electrons are
________________. a) majority charge carriers b) minority charge carriers c) donor atoms d) acceptor
atoms 28.] In a n-type semiconductor material holes are ________________. a) majority charge carriers
b) minority charge carriers c) donor atoms d) acceptor atoms 29.] The pentavalent impurity atom, like
arsenic, added to pure germanium material is termed as ____________. a) majority charge carriers b)
minority charge carriers c) donor atoms d) acceptor atoms 30.] If a trivalent impurity like gallium or
indium or aluminium is added to pure germanium or silicon, a _____________________ results. a)
intrinsic semiconductor b) extrinsic semiconductor c) p-type semiconductor d) n-type semiconductor
31.] In a p-type semiconductor material holes are ________________. a) majority charge carriers b)
minority charge carriers c) donor atoms d) acceptor atoms

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32.] In a p-type semiconductor material electrons are ________________. a) majority charge carriers b)
minority charge carriers c) donor atoms d) acceptor atoms 33.] The trivalent impurity atom, like gallium,
added to pure germanium material is termed as ____________. a) majority charge carriers b) minority
charge carriers c) donor atoms d) acceptor atoms 34.] In extrinsic semiconductors, conduction of current
is due to ____________. a) electrons only b) holes only c) both electrons and holes d) neither electrons
nor holes 35.] Doping an intrinsic semiconductor with pentavalent impurity __________________. a)
raises the Fermi level b) lowers the Fermi level c) do not affect the Fermi level d) none of the above
atom

36.] Doping an intrinsic semiconductor with trivalent impurity atom __________. a) raises the Fermi
level b) lowers the Fermi level c) do not affect the Fermi level d) none of the above 37.] In a pure
semiconductor, the Fermi level lies _____________ of the forbidden energy gap. a) exactly in the middle
b) at the lower part c) at the upper part d) none of the above 38.] In a p-n junction, the potential built
across the junction, after diffusion has stopped, is termed as _______________. a) barrier potential b)
developed potential c) p-n potential d) none of the above 39.] The barrier potential is about
______________ of germanium. a) 0.1V b) 0.3V c) 0.7V d) 1.5V 40.] The barrier potential is about
______________ of silicon. a) 0.1V b) 0.3V c) 0.7V d) 1.5V 41.] If an external voltage is applied across the
p-n junction such that it neutralizes the barrier potential and causes conduction through the junction,
the pn junction is said to be ______________. a) forward biased b) reverse biased c) un-biased d) no-
biased

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42.] If an external voltage is applied across the p-n junction such that the depletion layer widens and the
barrier potential increases, the p-n junction is said to be ______________. a) forward biased b) reverse
biased c) un-biased d) no-biased 43.] A p-n junction conducts when it is _________________. a) forward
biased b) reverse biased c) un-biased d) no-biased 44.] A p-n junction blocks conduction when it is
________________. a) forward biased b) reverse biased c) un-biased d) no-biased 45.] The direction of
conventional current is always ____________ to the direction of drifting electrons. a) same b) opposite
c) cant say d) none of the above 46.] The slope of DC load line is _______________. a) 1/IL b) 1/VL c)
1/RL d) 1/If 47.] The Iav for a half-wave rectifier is _____________. a) Im/
48.] The IRMS for a half-
for a full- for a full-
wave rectifier is _____________. a) Im/ -wave
rectifier is _____________. a) 40.6% b) 81.2% c) 0.483% d) 1.21% 52.] The efficiency of a full-wave
rectifier is _____________. a) 40.6% b) 81.2% c) 0.483% d) 1.21%

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53.] The ripple factor of a half-wave rectifier is _____________. a) 40.6 b) 81.2 c) 0.483 d) 1.21 54.] The
ripple factor of a full-wave rectifier is _____________. a) 40.6 b) 81.2 c) 0.483 d) 1.21 55.] An inductor
___________ to pass through it. a) allows DC b) blocks DC c) allows AC d) blocks AC 56.] A capacitor
___________ to pass through it. a) allows DC b) blocks DC c) allows AC d) blocks AC 57.] The switch off
time of diodes is longer due to _______________. a) the diffusion capacitance b) the forward bias c) the
reverse bias d) none of the above

UNIT 2 & 3: TRANSISTORS & BIASING METHODS 1.] The direction of arrow head placed on the emitter of
a transistor represents ________________. 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.] The direction of flow of electrons is
____________ to the direction of motion of holes. a) same as b) opposite c) parallel d) perpendicular 3.]
During normal working of transistor as amplifier, the emitter diode is ______________. a) unbiased b)
forward biased c) reverse biased d) none of the above 4.] During normal working of transistor as
amplifier, the collector diode is ______________. 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) base current b) emitter current

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c) collector current d) collector-to-base leakage current

6.] A transistor can be visualized as a ___________ port network. a) one b) two c) three d) four 7.]
Varying the input current by varying the input voltage at constant output voltage is
_____________________. a) static input characteristics b) static output characteristics c) transistor i/o
characteristics d) none of the above 8.] Varying the output current by varying the output voltage at
constant input current is _____________________. a) static input characteristics b) static output
characteristics c) transistor i/o characteristics d) none of the above 9.] The ratio of change in collector
current to the change in emitter current at constant collector to base voltage is ___________. a) b)
c) d) 10.] The ratio of change in collector current to the change in base current at constant collector
to emitter voltage is ___________. a) b) c) d) 11.] a) c) The ratio of change in emitter current
to the change in base is ___________. b) d)

12.] A ______________ circuit has a very high input resistance and very low output resistance. a)
common base b) common emitter c) common collector d) none of the above 13.] In the saturation
region, the emitter-base & collector-base junctions are _________________ biased. a) forward b)
reverse c) unbiased d) none of these 14.] In the cut-off region, the emitter-base & collector-base
junctions are _________________ biased. a) forward b) reverse c) unbiased d) none of these 15.] The
intersection of DC load line and the output characteristics of a transistor is called
_____________________. a) Q Point b) quiescent Point

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c) operating Point d) all of these

16.] The biasing circuit which gives most stable operating point is _________. a) base bias b) collector-
to-base bias c) voltage-divider bias d) none of these 17.] The collector-to-base bias circuit is also known
as _______________. a) base bias b) voltage-divider bias c) voltage feedback bias circuit d) none of
these 18.] The reverse saturation current doubles for every _________ temperature. a) 40 b) 30 c) 20 d)
10 19.] The reverse temperature. a) doubles c) quadruples saturation current __________ for every
0

C rise in

10 0C

rise

in

b) triples d) none of these

20.] ICBO doubles for every _________ 0C rise in temperature. a) 40 b) 30 c) 20 d) 10 21.] ICBO
__________ for every 100C rise in temperature. a) doubles b) triples c) quadruples d) none of these 22.]
The stability factor S is the rate change of _____________ current with respect to reverse saturation
current. a) emitter b) base c) collector d) none of these 23.] 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 24.] is the ratio of change in __________ current to the change in base
current at constant collector to emitter voltage. a) emitter b) base c) collector d) none of these 25.] is
the ratio of change in __________ current to the change in base current. a) emitter b) base c) collector
d) none of these

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26.] is the ratio of change in collector current to the change in _________ current at constant collector
to base voltage. a) emitter b) base c) collector d) none of these 27.] is the ratio of change in collector
current to the change in _________ current at constant collector to emitter voltage. a) emitter b) base c)
collector d) none of these 28.] is the ratio of change in emitter current to the change in _________
current. a) emitter b) base c) collector d) none of these 29.] The emitter area in a transistor is
considerably __________ than the collector area. a) smaller b) greater c) smaller or greater d) none of
these 30.] The collector area is slightly _________ doped than the emitter. a) more b) less c) more or
less d) none of these 31.] The depletion layer width at the collector junction is _________ than the
depletion layer width at the emitter junction. a) more b) less c) more or less d) none of these 32.] In a
transistor, the emitter area is _________ doped. a) heavily b) lightly c) moderately d) none of these 33.]
In a transistor, the base region is _________ doped. a) heavily b) lightly c) moderately d) none of these
34.] In a transistor, the collector area is _________ doped. a) heavily b) lightly c) moderately d) none of
these 35.] In a transistor, the depletion layer penetrates deeply into the __________ region. a) base b)
emitter c) collector d) none of these 36.] In a ______________, the current is mainly due to electrons.

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a) PNP transistor c) BJT transistor b) NPN transistor d) UJT transistor

37.] In a ______________, the current is mainly due to holes. a) PNP transistor b) NPN transistor c) BJT
transistor d) UJT transistor 38.] In CB configuration, when reverse bias voltage VCB increases, the width
of the depletion region also increases, which reduces the electrical base width. This effect is called as
_________________. a) early effect b) base width modulation c) (a) or (b) d) none of these 39.] In CB
configuration, when reverse bias voltage VCB increases above the VCB max, increase in depletion region
is such that it penetrates into base until it makes contact with emitter-base depletion region. This
condition is called _______. a) punch-through effect b) reach-through effect c) (a) or (b) d) none of these
40.] The collector-to-base bias provides __________ stability than the base bias circuit. a) more b) less c)
more or less d) none of these 41.] The voltage divider bias provides the _______ stability against hFE
variations. a) least b) greatest c) more or less d) none of these UNIT 5: AMPLIFIERS & OSCILLATORS 1.]
Audio amplifiers can amplify signals of frequencies which lie in the range of _____________. a) 20Hz to
20KHz b) 20Hz to 20MHz c) 20Hz to 200KHz d) 20Hz to 200MHz 2.] In a _________ amplifier, the
collector current flows throughout the input signal cycle. a) class A b) class B c) class C d) class AB 3.] In a
__________ amplifier, the collector current flows only during the positive half cycles of the input signal.
a) class A b) class B c) class C d) class AB 4.] In a ____________ amplifier, the collector current flows for
less than half of the period of the input signal.

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a) class A c) class C b) class B d) class AB

5.] In a ____________ amplifier, the collector current flows for more than half of the input signal period,
but not throughout the full cycle. a) class A b) class B c) class C d) class AB 6.] The coupling capacitor, CC,
in a R-C coupled amplifier is used to _________. 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.] The range of
frequencies in which the amplifier gain is either equal to greater than 70.7% of the maximum gain is
called as _______________. a) channel-width b) frequency-width c) band-width d) none of these 8.] The
range of frequencies at the limits of which, the voltage gain falls by 3dB is called as _______________. a)
channel-width b) frequency-width c) band-width d) none of these 9.] In a common-emitter amplifier,
there is a phase shift of _________ between input and output voltages. a) 900 b) 1800 c) 3600 d) 00 10.]
When the phase of the feedback signal is same as that of the input, then it is called ______________. a)
positive feedback b) negative feedback c) no feedback d) none of these 11.] When the phase of the
feedback signal is out of phase with that of the input, then it is called ______________. a) positive
feedback b) negative feedback c) no feedback d) none of these 12.] Tank circuit comprises of
_____________. 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.] R-C oscillators are usually
used in ___________ range. a) audio frequency b) radio frequency c) video frequency d) ultra high
frequency

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UNIT 6: OPERATIONAL AMPLIFIERS 1.] The characteristics of ______________ changes with application
of external voltage. a) an active element b) a passive element c) both (a) and (b) d) neither (a) nor (b) 2.]
The characteristics of ______________ will not change on application of external voltage. a) an active
element b) a passive element c) both (a) and (b) d) neither (a) nor (b) 3.] In _____________, the outputs
are proportional to inputs. a) digital ICs b) linear ICs c) both (a) and (b) d) neither (a) nor (b) 4.] In a
_____________, the inputs and outputs can take only two values; 0 and 1. a) digital ICs b) linear ICs c)
both (a) and (b) d) neither (a) nor (b) 5.] The voltage gain of an ideal Op-Amp is _____________. a)
infinity b) zero c) very high d) very low 6.] The input impedance of an ideal Op-Amp is _____________. a)
infinity b) zero c) very high d) very low 7.] The output impedance of an ideal Op-Amp is _____________.
a) infinity b) zero c) very high d) very low 8.] The bandwidth of an ideal Op-Amp is _____________. a)
infinity b) zero c) very high d) very low 9.] When equal voltages are applied to two input terminals of an
ideal Op-Amp, the output is ____________. a) infinity b) zero

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c) very high d) very low

10.] The voltage gain of a practical Op-Amp is _____________. a) infinity b) zero c) very high d) very low
11.] The input impedance of a practical Op-Amp is _____________. a) infinity b) zero c) very high d) very
low 12.] The output impedance of a practical Op-Amp is _____________. a) infinity b) zero c) very high
d) very low 13.] When equal voltages are applied to two input terminals of a practical OpAmp, the
output is ____________. a) infinity c) very high b) zero d) very low

14.] The ratio of the differential gain of an Op-Amp to its common mode gain is ______________. a)
PSRR b) input off-set current c) output off-set current d) CMRR 15.] In a practical Op-Amp, there will be a
small output voltage even when the inputs are zero. This is called _____________. a) output off-set
current b) output off-set voltage c) input off-set current d) input off-set voltage 16.] The DC voltage
which makes the output off-set voltage zero, when the other terminal is zero is called _____________.
a) output off-set current b) output off-set voltage c) input off-set current d) input off-set voltage 17.]
The maximum rate at which the Op-Amp output can change is ___________. a) run rate b) ratio rate c)
slew rate d) none of these 18.] Slew rate is expressed in terms of ______________.

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a) volts/s c) s/volts b) volts-s d) s-volts

19.] The time period for which the trace remains on a fluorescent screen after the applied signal
becomes zero is known as ____________. a) existence b) shadow c) persistence d) trace 20.] The time-
base generator in a CRO is used to generate _______________. a) the saw-tooth voltage b) the square
wave c) the DC voltage d) the AC voltage 21.] When the input is applied to the inverting input terminal
of an Op-Amp, then the output is ______________ with the input. 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 non-inverting input
terminal of an Op-Amp, then the output is ______________ with the input. 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.] If the amplitude of the carrier wave is
altered in accordance with the strength of the modulating signal, then it is _________________. a)
amplitude modulation b) frequency modulation c) amplitude communication d) frequency
communication 2.] If the frequency of the carrier wave is altered in accordance with the strength of the
modulating signal, then it is _________________. a) amplitude modulation b) frequency modulation c)
amplitude communication d) frequency communication 3.] The process of getting back the modulating
signal from the modulated wave is _________________. a) modulation b) re-modulation c)
demodulation d) none of these 4.] The modulation index m for amplitude modulation is
_____________. a) Vc/Vm b) Vc * Vm c) Vm + Vc d) Vm/Vc

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5.] The modulation index mf for frequency modulation is _____________. a) - fm
______________. a) 455 MHz b) 455 KHz c) 455 Hz
d) 455 GHz 9.] The decimal equivalent of binary number 1110 is ________________. a) 15 b) 16 c) 18 d)
14 10.] 110112 = X10, then a) X = 27 c) X = 17

b) X = 37 d) X = 12

11.] The 1s compliment of 1110 is __________. a) 1111 b) 0001 c) 0010 c) 0000 12.] The 2s compliment
of 1110 is ____________. a) 1111 b) 0001 c) 0010 d) 0000 13.] If 4710 = X8, then a) X = 37 b) X = 27 c) X =
74 d) X = 57 14.] The octal equivalent of 001001011011 (2) is _________________. a) 3311(8) b) 3113(8)
c) 1133(8) d) 1331(8) 15.] If 110211102 = X16, then a) X = AB c) X = EF 16.] If 5810 = XBCD, then a) X =
01011000 c) X = 10101000

b) X = CD d) X = DE

b) X = 01010001 c) 10100001

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UNIT 8: DIGITAL ELECTRONICS 1.] The OR operation implies ______________. a) boolean addition b)
boolean multiplication c) Boolean subtraction d) boolean division 2.] The AND operation implies
______________. a) boolean addition b) boolean multiplication c) Boolean subtraction d) boolean
division 3.] The output of a NAND gate is ___________, when all the inputs are high. a) low b) high c)
low or high d) none of these 4.] The output of a NOR gate is ___________, when all the inputs are low.
a) low b) high c) low or high d) none of these 5.] A bubbled AND gate and a _____________ are
equivalent. a) XOR gate b) XNOR gate c) NOR gate d) NAND gate 6.] A bubbled OR gate and a
_____________ are equivalent. a) XOR gate b) XNOR gate c) NOR gate d) NAND gate

____________***____________

By MAHESH PRASANNA K.,

Dept. of E & C, AIET.

MAHESH PRASANNA K., ECE, AIET

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