For online tests and competitive exams, here are the most important multiple choice questions (MCQs) on Analog Electronics
1.
The ratio of majority and minority carriers of
an intrinsic semiconductor ¡s
a)
Zero
b)
Infinity
c) Unity
d)
Very large
2.
A laser diode can be fabricated using
a)
Germanium
b)
Silicon
c) Gallium arsenide
d)
Gallium phosphide
3.
The ratio of majority and minority carriers of
an extrinsic semiconductor is-
a)
Zero
b)
Infinity
c)
Unity
d) Very large
4.
Resistivity of semiconductor depends on
a)
The length of the specimen
b)
Cross-sectional area of the specimen
c)
Volume of the specimen
d) Atomic nature of the semiconductor
5.
The depletion region in a Junction Diode
contains
a)
only charge carriers (of minority type and
majority type)
b)
no charge at all
c)
vacuum, and no atoms at all
d) only ions
6.
JFET is a
a)
Current controlled device with high input
resistance
b) Voltage controlled device with high input
resistance
c)
Current Controlled Current Source (CCCS)
d)
Voltage Controlled Voltage Source (VCVS)
7.
Photo-electric emission current is proportional
to
a) frequency of the incident light
b)
incident light flux
c)
work function of photo-cathode
d)
angle of incidence of radiation
8.
Which configuration has unity voltage gain
(ideal)
a) a Common Collector (CC)
b)
a Common Emitter (CE)
c)
a Common Base (CB)
d)
CE followed by CB
9.
Which of the following ¡s an active device
a)
an electric bulb
b)
a diode
c) a BJT
d)
a transformer
10.
An ideal differential amplifier has CMRR
equaling
a)
Unity
b)
-1 (minus unity)
c) Infinity
d)
Zero
11.
The majority charge carriers in the emitter of
an NPN transistor are
a)
pentavalent atoms
b)
trivalent atoms
c) electrons
d)
holes
12.
Which of the following doping will produce a
p-type semiconductor
a)
Germanium with phosphorus
b)
Silicon with Germanium
c)
Germanium with Antimony
d) Silicon with Indium
13.
A virtual ground
a)
is a ground for voltage
b)
is a ground for both voltage and current
c)
¡s ground for current
d) is a ground for voltage but not for current
14.
The minimum gate current which can turn on 5CR
is called-
a) trigger current
b)
holding current
c)
junction
d)
break over current
15.
Compared to bipolar transistor, a JFET has
a)
lower input impedance
b)
higher voltage gain
c)
higher input impedance and high voltage gain
d) higher input impedance and low voltage gain
16.
Which of the following diodes is operated in
reverse bias mode?
a)
P-N junction
b) Zener
c)
Tunnel
d)
Schottky
17.
An intrinsic semiconductor at the absolute zero temperature
a)
behaves like a metallic conductor
b) behaves like an insulator
c)
has a large number of holes
d)
has a large number of electrons
18.
An ideal voltage source of 12 V provides a
current of 150 mA to a load connected across ¡t. If the load impedance ¡s
halved, the new load current will be
a) 0.3A
b)
0.15 A
c)
0.GA
d)
1.2A
19.
Ratings on a capacitor are given 25uF, 12 V.
Also a plus sign is written near one of its terminals. The capacitor is
a)
mica capacitor
b)
ceramic capacitor
c) electrolytic capacitor
d)
paper capacitor
20.
A resistor used in colour TV has the following
colour bands: yellow, violet, orange and silver. Its nominal value is-
a)
4.7 KW ± 10 %
b)
4.7 KW ± 5%
c) 47 KW ± 10%
d)
470KW ± 5%
21.
An Op-amp as a voltage follower has a voltage
gain of-
a)
Infinity
b)
Zero
c) Unity
d)
less than unity
22.
The negative potential at the control grid in a
vacuum triode that causes plate current Zero is called
a) cut off bias
b)
cut in voltage
c)
reverse blocking voltage
d)
forward blocking voltage
23.
In an 5CR the holding current is-
a)
more than latching current
b) less than latching current
c)
equal to latching current
d)
very small
24.
A transistor ¡n common emitter mode has
a)
a high input resistance and low output
resistance
b) a medium input resistance and high output
resistance
c)
a very low input resistance and a low output
resistance
d)
a high input resistance and a high output
resistance
25.
The diode in which impurities are heavily doped
is-
a)
Varactor diode
b)
PIN diode
c) Tunnel diode
d)
Zener diode
26.
The varactor diode is usually
a)
Forward biased
b) reverse biased
c)
Unbiased
d)
holes and electronics
27.
Avalanche breakdown results basically due to
a) impact ionization
b)
strong electric field across the junction
c)
emission of electrons
d)
rise in temperature
28.
In integrated circuits, npn construction is
preferred to pnp construction because
a)
npn construction is cheaper
b) to reduce diffusion constant, n-type
collector is preferred
c)
npn construction permits higher packing of
elements
d)
p-type base is preferred
29.
The negative-resistance region of tunnel diodes
can be used in the design of
a)
oscillators
b)
switching networks
c)
pulse generators
d) All of the above
30.
In the negative-resistance region of tunnel
diodes, as the terminal voltage increases, the diode current
a)
remains the same
b) decreases
c)
increases
d)
is undefined
31.
The normal range of reverse-bias voltage VR for
varactor diodes is limited to about
a)
15V
b) 20V
c)
25V
d)
40V
32.
Varactor diodes are
a)
semiconductor devices
b)
voltage-dependent
c)
variable capacitors
d) All of the above
33.
Ply of Schottky diodes ¡s usually _______that of
a comparable p-n junction un it
a)
1/2
b) 1/3
c)
1/4
d)
1/5
34.
Schottky diodes have —
a)
quick response time
b)
a lower noise figure
c) both quick response time and a lower noise
figure
d)
None of the above
35.
Which of the following diodes is limited to the
reverse bias region in its region of operation?
a)
Schottky
b)
Tunnel
c) Photodiode
d)
Rectifier
36.
In which region is the operating point stable in
tunnel diodes?
a)
Negative-resistance
b) Positive-resistance
c)
Both negative- and positive-resistance
d)
Neither negative- nor positive-resistance
37.
What is the maximum peak voltage for tunnel
diodes?
a)
50 mV
b)
loo mV
c)
250 mV
d) 600 mV
38.
What is the limit of peak current IP ¡n tunnel
diodes?
a) A few microamperes to several hundred
amperes
b)
A few microamperes to several amperes
c)
A few microamperes to several milli amperes
d)
A few microamperes to several hundred
microamperes
39.
Which of the following diodes has a
negative-resistance region?
a)
Schottky
b)
Varactor
c) Tunnel
d)
Power
40.
Which of the following areas is (are)
applications of varactor diodes?
a)
FM modulators
b)
Automatic-frequency control devices
c)
Adjustable band pass filters
d) All of the above
41.
Schottky diodes are very effective at
frequencies approaching —
a) 20 GHz
b)
10 MHz
c)
100 MHz
d)
1MHz
42.
What is the voltage drop across Schottky diodes?
a) 10 V to 0.2 V
b)
0.7 V to 0.8 V
c)
0.8 V to 1.0V
d)
1.0 V to 1.5 V
43.
A Schottky transistor used as a switch operates
between
a)
Cut-off and saturation regions
b) Cut-off and active regions
c)
Active and saturation regions
d)
None of these
44.
Which one of the following is a unique
characteristic of Schottky transistor?
a) Lower propagation delay
b)
Higher propagation delay
c)
Lower power dissipation
d)
Higher power dissipation
45.
Temperature coefficient of resistance of a pure
semiconductor specimen ¡s
a)
Zero
b)
Positive
c) Negative
d)
None of the above