Explore topic-wise MCQs in Electrical Engineering.

This section includes 78 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.

51.

_ A crystal diode has$?

A. one pn junction
B. two pn junctions
C. three pn junctions
D. none of the above
Answer» B. two pn junctions
52.

_ The ratio of reverse resistance and forward resistance of a germanium crystal diode is about ___________$?

A. 1 : 1
B. 100 : 1
C. 1000 : 1
D. 40000 : 1
Answer» E.
53.

_ Mains a.c. power is converrted into d.c. power for ___________$?

A. lighting purposes
B. heaters
C. using in electronic equipment
D. none of the above
Answer» D. none of the above
54.

_ When the graph between current through and voltage across a device is a straight line, the device is referred to as ___________$?

A. linear
B. active
C. nonlinear
D. passive
Answer» B. active
55.

_ The most widely used rectifier is ___________$?

A. half-wave rectifier
B. centre-tap full-wave rectifier
C. bridge full-wave rectifier
D. none of the above
Answer» D. none of the above
56.

_ ___________ rectifier has the lowest forward resistance$?

A. solid state
B. vacuum tube
C. gas tube
D. none of the above
Answer» B. vacuum tube
57.

_ If the temperature of a crystal diode increases, then leakage current ___________$?

A. remains the same
B. decreases
C. increases
D. becomes zero
Answer» D. becomes zero
58.

_A crystal diode is a ___________ device$?

A. non-linear
B. bilateral
C. linear
D. none of the above
Answer» B. bilateral
59.

_The forward voltage drop across a silicon diode is about ___________$?

A. 2.5 V
B. 3 V
C. 10 V
D. 0.7 V
Answer» E.
60.

_The reverse current in a diode is of the order of ___________$?

A. kA
B. mA
C. μA
D. A
Answer» D. A
61.

_The PIV rating of each diode in a bridge rectifier is ___________ that of the equivalent centre-tap rectifier$?

A. one-half
B. the same as
C. twice
D. four times
Answer» B. the same as
62.

_The maximum efficiency of a half-wave rectifier is ___________$?

A. 40.6%
B. 81.2%
C. 50%
D. 25%
Answer» B. 81.2%
63.

_A zener diode utilizes ___________ characteristics for its operation.$?

A. forward
B. reverse
C. both forward and reverse
D. none of the above
Answer» C. both forward and reverse
64.

_When the crystal current diode current is large, the bias is ___________$?

A. forward
B. inverse
C. poor
D. reverse
Answer» B. inverse
65.

A zener diode is always ___________ connected.?

A. reverse
B. forward
C. either reverse or forward
D. none of the above
Answer» B. forward
66.

A series resistance is connected in the zener circuit to___________?

A. properly reverse bias the zener
B. protect the zener
C. properly forward bias the zener
D. none of the above
Answer» C. properly forward bias the zener
67.

A crystal diode has forward resistance of the order of ___________?

A. kΩ
B. Ω
C. MΩ
D. none of the above
Answer» C. M≈í¬©
68.

When a crystal diode is used as a rectifier, the most important consideration is ___________?

A. forward characteristic
B. doping level
C. reverse characteristic
D. PIC rating
Answer» E.
69.

The ripple factor of a half-wave rectifier is ___________?

A. 2
B. 1.21
C. 2.5
D. 0.48
Answer» E.
70.

The leakage current in a crystal diode is due to ___________?

A. minority carriers
B. majority carriers
C. junction capacitance
D. none of the above
Answer» B. majority carriers
71.

In the breakdown region, a zener didoe behaves like a ___________ source.

A. constant voltage
B. constant current
C. constant resistance
D. none of the above
Answer» B. constant current
72.

A zener diode has ___________ breakdown voltage

A. undefined
B. sharp
C. zero
D. none of the above
Answer» C. zero
73.

If the doping level in a crystal diode is increased, the width of depletion layer___________

A. remains the same
B. is decreased
C. in increased
D. none of the above
Answer» D. none of the above
74.

If the doping level of a crystal diode is increased, the breakdown voltage___________

A. remains the same
B. is increased
C. is decreased
D. none of the above
Answer» D. none of the above
75.

If the a.c. input to a half-wave rectifier is an r.m.s value of 400/‚Äö√ √∂2 volts, then diode PIV rating is ___________#

A. 400/‚Äö√ √∂2 V
B. 400 V
C. 400 x ‚Äö√ √∂2 V
D. none of the above
Answer» C. 400 x ‚Äö√ √∂2 V
76.

A crystal diode utilises ___________ characteristic for rectification

A. reverse
B. forward
C. forward or reverse
D. none of the above
Answer» C. forward or reverse
77.

A zener diode is ___________ device

A. a non-linear
B. a linear
C. an amplifying
D. none of the above
Answer» B. a linear
78.

If the arrow of crystal diode symbol is positive w.r.t. bar, then diode is ___________ biased.

A. forward
B. reverse
C. either forward or reverse
D. none of the above
Answer» B. reverse