Chapter Fourteen
SEMICONDUCTOR
ELECTRONICS
MATERIALS, DEVICES
AND SIMPLE CIRCUITS
MCQ I
14.1 The conductivity of a semiconductor increases with increase in
temperature because
(a) number density of free current carriers increases.
(b) relaxation time increases.
(c) both number density of carriers and relaxation time increase.
(d) number density of current carriers increases, relaxation time
decreases but effect of decrease in relaxation time is much less
than increase in number density. 1
2
14.2 In Fig. 14.1, Vo is the potential barrier across a p-n 3
junction, when no battery is connected across the junction
V0
(a) 1 and 3 both correspond to forward bias of junction
(b) 3 corresponds to forward bias of junction and 1
corresponds to reverse bias of junction
(c) 1 corresponds to forward bias and 3 corresponds to reverse
bias of junction. Fig. 14.1
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, Exemplar Problems–Physics
(d) 3 and 1 both correspond to reverse bias of junction.
14.3 In Fig. 14.2, assuming the diodes to be ideal,
(a) D1 is forward biased and D2 is reverse biased and hence current
flows from A to B
(b) D2 is forward biased and D1 is reverse biased and hence no
current flows from B to A and vice versa.
(c) D1and D2 are both R D1
A
forward biased –10V
and hence
current flows
from A to B. D2
(d) D 1 and D 2 are
both reverse Fig. 14.2 B
biased and hence
no current flows
from A to B and vice versa.
14.4 A 220 V A.C. supply is connected between points A and B
(Fig. 14.3). What will be the potential difference V across the
capacitor?
(a) 220V.
A (b) 110V.
(c) 0V.
220V C V
A.c. (d) 220 2 V.
B
Fig. 14.3 14.5 Hole is
(a) an anti-particle of electron.
(b) a vacancy created when an electron leaves a covalent bond.
(c) absence of free electrons.
(d) an artifically created particle.
14.6 The output of the given circuit in Fig. 14.4.
(a) would be zero at all times.
(b) would be like a half wave rectifier with positive
cycles in output.
(c) would be like a half wave rectifier with negative
vm sin t ~ cycles in output.
(d) would be like that of a full wave rectifier.
Fig. 14.4
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21/04/2018
SEMICONDUCTOR
ELECTRONICS
MATERIALS, DEVICES
AND SIMPLE CIRCUITS
MCQ I
14.1 The conductivity of a semiconductor increases with increase in
temperature because
(a) number density of free current carriers increases.
(b) relaxation time increases.
(c) both number density of carriers and relaxation time increase.
(d) number density of current carriers increases, relaxation time
decreases but effect of decrease in relaxation time is much less
than increase in number density. 1
2
14.2 In Fig. 14.1, Vo is the potential barrier across a p-n 3
junction, when no battery is connected across the junction
V0
(a) 1 and 3 both correspond to forward bias of junction
(b) 3 corresponds to forward bias of junction and 1
corresponds to reverse bias of junction
(c) 1 corresponds to forward bias and 3 corresponds to reverse
bias of junction. Fig. 14.1
21/04/2018
, Exemplar Problems–Physics
(d) 3 and 1 both correspond to reverse bias of junction.
14.3 In Fig. 14.2, assuming the diodes to be ideal,
(a) D1 is forward biased and D2 is reverse biased and hence current
flows from A to B
(b) D2 is forward biased and D1 is reverse biased and hence no
current flows from B to A and vice versa.
(c) D1and D2 are both R D1
A
forward biased –10V
and hence
current flows
from A to B. D2
(d) D 1 and D 2 are
both reverse Fig. 14.2 B
biased and hence
no current flows
from A to B and vice versa.
14.4 A 220 V A.C. supply is connected between points A and B
(Fig. 14.3). What will be the potential difference V across the
capacitor?
(a) 220V.
A (b) 110V.
(c) 0V.
220V C V
A.c. (d) 220 2 V.
B
Fig. 14.3 14.5 Hole is
(a) an anti-particle of electron.
(b) a vacancy created when an electron leaves a covalent bond.
(c) absence of free electrons.
(d) an artifically created particle.
14.6 The output of the given circuit in Fig. 14.4.
(a) would be zero at all times.
(b) would be like a half wave rectifier with positive
cycles in output.
(c) would be like a half wave rectifier with negative
vm sin t ~ cycles in output.
(d) would be like that of a full wave rectifier.
Fig. 14.4
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