Explore topic-wise MCQs in Electronics.

This section includes 217 Mcqs, each offering curated multiple-choice questions to sharpen your Electronics knowledge and support exam preparation. Choose a topic below to get started.

1.

What is the color code for a 220 5% resistor?

A. Red, Red, Brown, Gold
B. Orange, Orange, Black, Gold
C. Red, Red, Black, Gold
D. Red, Red, Brown, Silver
Answer» B. Orange, Orange, Black, Gold
2.

Which unit of charge contains 6.25 × 10electrons?

A. An ampere
B. A coulomb
C. A volt
D. A joule
Answer» C. A volt
3.

The symbol that represents electrical charge is .

A. True
B. False
Answer» B. False
4.

A resistor color coded with brown, black, and orange bands has a value of 10 k.

A. True
B. False
Answer» B. False
5.

A normally open push-buttonswitch can carry current when not pushed.

A. True
B. False
Answer» C.
6.

The battery symbol is:

A. [A].
B. [B].
C. [C].
D. [D].
Answer» C. [C].
7.

Which unit of charge contains 6.25 × 1018 electrons?

A. An ampere
B. A coulomb
C. A volt
D. A joule
Answer» C. A volt
8.

When one sine wave passes through the zero following the other, it is _________

A. Leading
B. Lagging
C. Neither leading nor lagging
D. Either leading or lagging
Answer» C. Neither leading nor lagging
9.

A phasor has frozen at 30 degrees, find the value of the phase angle.

A. 30 degrees
B. 60 degrees
C. 120 degrees
D. 180 degrees
Answer» B. 60 degrees
10.

The rms value is _________ times the maximum value.

A. 1.414
B. 0.5
C. 2
D. 0.707
Answer» E.
11.

Ammeters and voltmeters are calibrated to read?

A. RMS value
B. Peak value
C. Average value
D. Instantaneous value
Answer» B. Peak value
12.

Usually phasor diagrams are drawn representing?

A. RMS value
B. Peak value
C. Average value
D. Instantaneous value
Answer» B. Peak value
13.

The instantaneous values of two alternating voltages are given as:v1=60sinθ and v2=40sin(θ − π/3).Find the instantaneous difference.

A. 53 sin(71.5°) V
B. 53 sin( 79..5°) V
C. 53 sin(26.5°) V
D. 53 cos(36.5°) V
Answer» C. 53 sin(26.5°) V
14.

The rms value is 0.707 times the _________ value.

A. Peak
B. Instantaneous
C. Average
D. DC
Answer» B. Instantaneous
15.

The time axis of an AC phasor represents?

A. Time
B. Phase angle
C. Voltage
D. Current
Answer» C. Voltage
16.

The instantaneous values of two alternating voltages are given as:v1=60sinθ and v2=40sin(θ − π/3). Find the instantaneous sum.

A. 87.2 sin(36.5°) V
B. 87.2 sin( 0.5°) V
C. 87.2 sin(26.5°) V
D. 87.2 cos(36.5°) V
Answer» B. 87.2 sin( 0.5°) V
17.

For addition and subtraction of phasors, we use the _________ form.

A. Rectangular
B. Polar
C. Either rectangular or polar
D. Neither rectangular nor polar
Answer» B. Polar
18.

What is the correct expression of ω?

A. ω=2π
B. ω=2πf
C. ω=πf
D. ω=2f²
Answer» C. ω=πf
19.

The length of the phasor represents?

A. Magnitude of the quantity
B. Direction of the quantity
C. Neither magnitude nor direction
D. Either magnitude or direction
Answer» B. Direction of the quantity
20.

Find the value of ω if the frequency is 5Hz?

A. 3.14 rad/s
B. 31.4 rad/s
C. 34 rad/s
D. 341 rad/s
Answer» C. 34 rad/s
21.

If two current phasors, having magnitude 12A and 5A intersect at an angle of 90 degrees, calculate the resultant current.

A. 13 A
B. 10 A
C. 6 A
D. 5 A
Answer» B. 10 A
22.

If the phasors are drawn to represent the maximum values instead of the rms values, what would happen to the phase angle between quantities?

A. Increases
B. Decreases
C. Remains constant
D. Becomes zero
Answer» D. Becomes zero
23.

If two current phasors, having magnitude 5A and 10A intersect at an angle of 60 degrees, calculate the resultant current.

A. 12.23 A
B. 12.54 A
C. 13.23 A
D. 14.24 A
Answer» D. 14.24 A
24.

For multiplication and division of phasors, we use ____________ form.

A. Rectangular
B. Polar
C. Either rectangular or polar
D. Neither rectangular nor polar
Answer» C. Either rectangular or polar
25.

If the maximum value of the current is 5√2 A, what will be the value of the average current?

A. 10/π A
B. 5/π A
C. 15/π A
D. 25/π A
Answer» B. 5/π A
26.

Find the total current in the circuit if two currents of 4+5j flow in the circuit.

A. 4+5j A
B. 4A
C. 5A
D. 8+10j A
Answer» E.
27.

If a voltage of 2+5j and another voltage of 3+ 6j flows through two different resistors, connected in series, in a circuit, find the total voltage in the circuit.

A. 2+5j V
B. 3+6j V
C. 5+11j V
D. 5+10j V
Answer» D. 5+10j V
28.

Calculate the number of revolutions if the frequency is 15kHz and the paired poles are 50.

A. 100
B. 200
C. 300
D. 400
Answer» D. 400
29.

Calculate the frequency if the number of revolutions is 300 and the paired poles are 50.

A. 15kHz
B. 150kHz
C. 1500kHz
D. 150Hz
Answer» B. 150kHz
30.

What is the frequency of a two pole machine having n=50?

A. 100Hz
B. 200Hz
C. 50Hz
D. 25Hz
Answer» D. 25Hz
31.

What happens to the frequency if the number of pairs of poles increases?

A. Increases
B. Decreases
C. Remains the same
D. Becomes zero
Answer» B. Decreases
32.

Calculate the number of paired poles if the frequency id 15kHz and the number of revolutions is 300.

A. 10
B. 30
C. 50
D. 70
Answer» D. 70
33.

For a rectangular wave, average current is ______ rms current.

A. Greater than
B. Less than
C. Equal to
D. Not related
Answer» D. Not related
34.

In a sinusoidal wave, average current is always _______ rms current.

A. Greater than
B. Less than
C. Equal to
D. Not related
Answer» C. Equal to
35.

__________ current is found by dividing the area enclosed by the half cycle by the length of the base of the half cycle.

A. RMS current
B. Average current
C. Instantaneous current
D. Total current
Answer» C. Instantaneous current
36.

What is the effective value of current?

A. RMS current
B. Average current
C. Instantaneous current
D. Total current
Answer» B. Average current
37.

Peak value divided by the rms value gives us?

A. Peak factor
B. Crest factor
C. Both peak and crest factor
D. Neither peak nor crest factor
Answer» D. Neither peak nor crest factor
38.

Which is the correct formula for frequency in an ac generator?

A. f=p*n
B. f=p/n
C. f=n/p
D. f=n²p
Answer» B. f=p/n
39.

When is the shape of the negative half of the emf waveform equal to the positive half?

A. When the conductors move past north pole
B. When conductors move past south pole
C. When conductors move past both north and south pole
D. When conductors are stationary
Answer» D. When conductors are stationary
40.

The waveform of the emf generated undergoes one complete cycle when?

A. Conductors move past north pole
B. Conductors move past south pole
C. Conductors move past north and south poles
D. Conductors are stationary
Answer» D. Conductors are stationary
41.

If the peak voltage is 9V, calculate the peak to peak voltage.

A. 9V
B. 20V
C. 18V
D. 12V
Answer» D. 12V
42.

What is the minimum number of poles that a machine must have __________

A. 1
B. 2
C. 4
D. 10
Answer» C. 4
43.

What is the type of current obtained by finding the square of the currents and then finding their average and then fining the square root?

A. RMS current
B. Average current
C. Instantaneous current
D. Total current
Answer» B. Average current
44.

What will happen to the frequency if the number of revolutions increases?

A. Increases
B. Decreases
C. Remains the same
D. Becomes zero
Answer» B. Decreases
45.

What is the current found by finding the current in an equidistant region and dividing by n?

A. RMS current
B. Average current
C. Instantaneous current
D. Total current
Answer» C. Instantaneous current
46.

RMS stands for ________

A. Root Mean Square
B. Root Mean Sum
C. Root Maximum sum
D. Root Minimum Sum
Answer» B. Root Mean Sum
47.

Find the average value of current when the current that are equidistant are 4A, 5A and 6A.

A. 5A
B. 6A
C. 15A
D. 10A
Answer» B. 6A
48.

The resultant of two alternating sinusoidal voltages or currents can be found using ___________

A. Triangular law
B. Parallelogram law
C. Either triangular or parallelogram law
D. Neither triangular nor parallelogram law
Answer» C. Either triangular or parallelogram law
49.

If maximum value of current is 5√2 A, what will be the value of RMS current?

A. 10 A
B. 5 A
C. 15 A
D. 25 A
Answer» C. 15 A
50.

Calculate the crest factor if the peak value of current is 10A and the rms value is 2A.

A. 5
B. 10
C. 5A
D. 10A
Answer» B. 10