Q.91 The number of minority charge carriers crossing the junction is mainly depend on _____ in PN junction diode.
A. rate of thermal generation of electron-hole pairs
B. reverse biased
C. forward biased
D. barrier potential
Ans.: A
Q.92 What is the junction current at equilibrium when a PN junction diode is unbiased?
A. minority charge carriers
B. majority charge carriers
C. zero
D. infinite
Ans.: C
Q.93 The current through the junction is increases at ______ in a reverse biased PN junction.
A. breakdown voltage
B. zero voltage
C. 0.3 V
D. 0.12 V
Ans.: A
Q.94 If the battery voltage is increasing ________ when PN junction diode is under forward biased condition.
A. current through PN junction reduced to zero
B. no current flow through the junction
C. current through PN junction remains constant
D. current through PN junction increases
Ans.: D
Q.95 What is the value of current in PN junction under reversed biased condition?
A. few micro amperes
B. 2 to 3 Ampere
C. few nano amperes
D. Both A or C
Ans.: D
Q.96 What is the maximum efficiency of half wave rectifier?
A. 85%
B. 100%
C. 40.6%
D. 75%
Ans.: C
Q.97 Half wave rectifier need____ diode.
A. two
B. four
C. eight
D. one
Ans.: D
Q.98 The ripple factor of half wave rectifier is ___
A. 0.482
B. 0.856
C. 1.21
D. 0.7
Ans.: C
Q.99 In full wave rectifiers the maximum efficiency is ____
A. 81.2%
B. 100%
C. 50.6%
D. 95%
Ans.: A
Q.100 Ripple factor of full wave rectifier is
A. 0.8
B. 0.482
C. 1.21
D. 1
Ans.: B
Q.101 The power diodes are generally made up of ___.
A. Arsenic diode
B. Silicon diode
C. Germanium diode
D. Boron
Ans.: B
Q.102 The semi conductor is _____ before doping.
A. purified
B. heating
C. crystallization
D. all of the above
Ans.: A
Q.103 ____ needs four diodes.
A. full wave rectifier
B. bridge rectifier
C. centre-tap full wave rectifier
D. all of the above
Ans.: B
Q.104 _____ is designed to operate in breakdown region.
A. LED
B. Gunn diode
C. Zener diode
D. power diode
Ans.: C
Q.105 The avalanche breakdown in a semi conductor occurs when _____
A. forward bias exceeds a certain value
B. barrier potential exceeds certain value
C. reverse bias exceeds a certain value
D. barrier potential reduced
Ans.: C