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.

1.

A 1,000 V power supply would use_____________ as a filter capacitor?

A. paper capacitor
B. air capacitor
C. mica capacitor
D. electrolytic capacitor
Answer» B. air capacitor
Discussion
2.

A 10 V power supply would use ____________ as filter capacitor?

A. paper capacitor
B. mica capacitor
C. electrolytic capacitor
D. air capacitor
Answer» D. air capacitor
Discussion
3.

A zener diode is destroyed if it___________

A. is forward biased
B. is reverse biased
C. carrier more than rated current
D. none of the above
Answer» D. none of the above
Discussion
4.

If the PIV rating of a diode is exceeded, ___________

A. the diode conducts poorly
B. the diode is destroyed
C. the diode behaves like a zener diode
D. none of the above
Answer» C. the diode behaves like a zener diode
Discussion
5.

An ideal crystal diode is one which behaves as a perfect ___________ when forward biased.

A. conductor
B. insulator
C. resistance material
D. none of the above
Answer» B. insulator
Discussion
6.

The ___________ filter circuit results in the best voltage regulation

A. choke input
B. capacitor input
C. resistance input
D. none of the above
Answer» B. capacitor input
Discussion
7.

The doping level in a zener diode is ___________ that of a crystal diode

A. the same as
B. less than
C. more than
D. none of the above
Answer» D. none of the above
Discussion
8.

___________ rectifier has the lowest forward resistance

A. solid state
B. vacuum tube
C. gas tube
D. none of the above
Answer» B. vacuum tube
Discussion
9.

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
Discussion
10.

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
Discussion
11.

There is a need of transformer for ___________

A. half-wave rectifier
B. centre-tap full-wave rectifier
C. bridge full-wave rectifier
D. none of the above
Answer» C. bridge full-wave rectifier
Discussion
12.

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
Discussion
13.

The reverse current in a diode is of the order of ___________

A. kA
B. mA
C. μA
D. A
Answer» D. A
Discussion
14.

A crystal diode has forward resistance of the order of ___________

A. kΩ
B. Ω
C. MΩ
D. none of the above
Answer» C. MΩ
Discussion
15.

The d.c. resistance of a crystal diode is ___________ its a.c. resistance

A. the same as
B. more than
C. less than
D. none of the above
Answer» D. none of the above
Discussion
16.

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
Discussion
17.

When the crystal current diode current is large, the bias is ___________

A. forward
B. inverse
C. poor
D. reverse
Answer» B. inverse
Discussion
18.

The PIV rating of a crystal diode is ___________ that of equivalent vacuum diode

A. the same as
B. lower than
C. more than
D. none of the above
Answer» C. more than
Discussion
19.

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.
Discussion
20.

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.
Discussion
21.

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
Discussion
22.

The knee voltage of a crystal diode is approximately equal to ___________

A. applied voltage
B. breakdown voltage
C. forward voltage
D. barrier potential
Answer» E.
Discussion
23.

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
Discussion
24.

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
Discussion
25.

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.
Discussion
26.

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

A. 400/√2 V
B. 400 V
C. 400 x √2 V
D. none of the above
Answer» C. 400 x √2 V
Discussion
27.

A zener diode has ___________

A. one pn junction
B. two pn junctions
C. three pn junctions
D. none of the above
Answer» B. two pn junctions
Discussion
28.

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
Discussion
29.

The maximum efficiency of a half-wave rectifier is ___________

A. 40.6%
B. 81.2%
C. 50%
D. 25%
Answer» B. 81.2%
Discussion
30.

The ripple factor of a half-wave rectifier is ___________

A. 2
B. 1.21
C. 2.5
D. 0.48
Answer» C. 2.5
Discussion
31.

A 10 V power supply would use ___________ as filter capacitor.

A. paper capacitor
B. mica capacitor
C. electrolytic capacitor
D. air capacitor
Answer» D. air capacitor
Discussion
32.

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
Discussion
33.

A crystal diode is a ___________ device

A. non-linear
B. bilateral
C. linear
D. none of the above
Answer» B. bilateral
Discussion
34.

A zener diode is always ___________ connected.

A. reverse
B. forward
C. either reverse or forward
D. none of the above
Answer» B. forward
Discussion
35.

A half-wave rectifier has an input voltage of 240 V r.m.s. If the step-down transformer has a turns ratio of 8:1, what is the peak load voltage? Ignore diode drop.

A. 27.5 V
B. 86.5 V
C. 30 V
D. 42.5 V
Answer» E.
Discussion
36.

A zener diode is used as ___________

A. an amplifier
B. a voltage regulator
C. a rectifier
D. a multivibrator
Answer» C. a rectifier
Discussion
37.

A crystal diode is used as ___________

A. an amplifier
B. a rectifier
C. an oscillator
D. a voltage regulator
Answer» C. an oscillator
Discussion
38.

The disadvantage of a half-wave rectifier is that the___________

A. components are expensive
B. diodes must have a higher power rating
C. output is difficult to filter
D. none of the above
Answer» D. none of the above
Discussion
39.

For the same secondary voltage, the output voltage from a centre-tap rectifier is ___________ than that of bridge rectifier

A. twice
B. thrice
C. four time
D. one-half
Answer» E.
Discussion
40.

A zener diode is destroyed if it___________%!

A. is forward biased
B. is reverse biased
C. carrier more than rated current
D. none of the above
Answer» D. none of the above
Discussion
41.

If the PIV rating of a diode is exceeded, ___________%!

A. the diode conducts poorly
B. the diode is destroyed
C. the diode behaves like a zener diode
D. none of the above
Answer» C. the diode behaves like a zener diode
Discussion
42.

An ideal crystal diode is one which behaves as a perfect ___________ when forward biased.%!

A. conductor
B. insulator
C. resistance material
D. none of the above
Answer» B. insulator
Discussion
43.

The ___________ filter circuit results in the best voltage regulation%!

A. choke input
B. capacitor input
C. resistance input
D. none of the above
Answer» B. capacitor input
Discussion
44.

*/*_A 10 V power supply would use ___________ as filter capacitor.?

A. paper capacitor
B. mica capacitor
C. electrolytic capacitor
D. air capacitor
Answer» D. air capacitor
Discussion
45.

*/*_The PIV rating of a crystal diode is ___________ that of equivalent vacuum diode?

A. the same as
B. lower than
C. more than
D. none of the above
Answer» C. more than
Discussion
46.

*/*_There is a need of transformer for ___________?

A. half-wave rectifier
B. centre-tap full-wave rectifier
C. bridge full-wave rectifier
D. none of the above
Answer» C. bridge full-wave rectifier
Discussion
47.

*/*_The knee voltage of a crystal diode is approximately equal to ___________?

A. applied voltage
B. breakdown voltage
C. forward voltage
D. barrier potential
Answer» E.
Discussion
48.

*/*_A zener diode has ___________?

A. one pn junction
B. two pn junctions
C. three pn junctions
D. none of the above
Answer» B. two pn junctions
Discussion
49.

*/*_The doping level in a zener diode is ___________ that of a crystal diode?

A. the same as
B. less than
C. more than
D. none of the above
Answer» D. none of the above
Discussion
50.

*/*_The d.c. resistance of a crystal diode is ___________ its a.c. resistance?

A. the same as
B. more than
C. less than
D. none of the above
Answer» D. none of the above
Discussion