TRANSISTORS,AMPLIFIERS & OSCILLATORS OBJECTIVE
TYPE QUESTIONS BASED ON DIPLOMA LEVEL SYLLABUS FOR THE
DRDO,DMRC,SSC,BHEL,RAILWAYS & OTHER ENGINEERING(DIPLOMA LEVEL)
COMPETITIVE EXAMS
1. 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
2.
In a transistor, the emitter area is _________ doped.
3.
In a transistor, the base region is _________ doped.
a) heavily b) lightly c)
moderately d) none of these
4.
In a transistor, the collector area is _________ doped.
a) heavily b) lightly c) moderately d) none of these
5. In a transistor, the depletion layer penetrates
deeply into the __________region.
a)
base b) emitter c)
collector d) none of
these
6. In a ______________, the current is mainly due to
electrons.
a) PNP
transistor
b) NPN transistor
c)
BJT transistor
d) UJT transistor
7. In a ______________, the current is mainly due to
holes.
a)
PNP transistor
b) NPN transistor
c) BJT
transistor
d) UJT transistor
8. 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
9. 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
10. The collector-to-base bias provides __________
stability than the base bias circuit.
a)
more b) less c) more or less d) none of these
11. The voltage divider bias provides the _______
stability against hFE variations.
a) least b) greatest c) more or less d) none of these
12.
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
13.In
a _________ amplifier, the collector current flows throughout the input
signal cycle.
a) class A b) class B c) class C d) class AB
14.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
15.In
a ____________ amplifier, the collector current flows for less than half
of the period of
the input signal.
a) class A b) class B c) class
C d) class AB
16. 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
17. 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
18. The range
of frequencies at the limits of which, the voltage gain falls by 3dBis called
as
_______________.
a) channel-width b) frequency-width
c) band-width
d) none of these
19. In a common-emitter amplifier, there is a
phase shift of _________ between
input and
output voltages.
a) 900 b) 1800 c) 3600 d) 00
20. 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
21. 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
22. 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
23. R-C oscillators are usually used
in ___________ range.
a) audio frequency
b) radio frequency
c) video frequency
d) ultra high frequency
24. 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
25.
The ratio of change in collector current to the change in base current at constant
collector to emitter voltage is ___________.
a)α
b)β
c)γ
d)π
26. The ratio of change in emitter current to the change
in base is ___________.
a)α
b)β
c)γ
d)π
27. 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
28. In the saturation region, the emitter-base &
collector-base junctions
are _________________ biased.
a)
forward
b) reverse
c)
unbiased d)
none of these
29.The direction of flow of electrons is ____________ to
the direction of motion of holes.
a) same as
b) opposite
c)
parallel d)
perpendicular
30. During normal working of transistor as amplifier,
the emitter diode is ______________.
a) unbiased b) forward biased
c) reverse biased d) none of the above
0 comments:
Post a Comment