Basic Electrical Engineering (3110005) MCQs

MCQs of AC Circuits

Showing 31 to 40 out of 117 Questions
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31.

The peak value of a sine wave is 200 V. Its average value is _______

(a)

127.4 V
(b)

141.4 V
(c)

282.8 V
(d)

200 V
Answer:

Option (a)

32.

The RMS value of a sine wave is 100 A. Its peak value is ________

(a)

70.7 A
(b)

141.4 A
(c)

150 A
(d)

282.8 A
Answer:

Option (b)

33.

Two waves of the same frequency have opposite phase when the phase angle between them is ____

(a)

360 degree
(b)

180 degree
(c)

90 degree
(d)

0 degree
Answer:

Option (b)

34.

Power factor of an electrical circuit is equal to _____

(a)

R/Z
(b)

Cosine of phase angle difference between current and voltage
(c)

kW / kVA
(d)

All of the above
Answer:

Option (d)

35.

Power of the following circuit will be zero.

(a)

Resistive
(b)

Purely inductive
(c)

Purely capacitive
(d)

Both B and C
Answer:

Option (d)

36.

Power factor of incandescent bulb is ______

(a)

Zero
(b)

Lagging
(c)

Leading
(d)

Unity
Answer:

Option (d)

37.

The power factor of a D.C. circuit is always ______

(a)

Less than unity
(b)

Unity
(c)

Greater than unity
(d)

Zero
Answer:

Option (b)

38.

In a purely resistive circuit, the average power is _________ the peak power.

(a)

double
(b)

one-half of
(c)

one-fourth
(d)

equal to
Answer:

Option (b)

39.

The power measurement in a balanced three-phase circuit can be done by

(a)

one wattmeter method only
(b)

two wattmeter method only
(c)

three wattmeter method only
(d)

any of the above
Answer:

Option (d)

40.

The unit of resistance is ________

(a)

Henry
(b)

millihenry
(c)

Wb
(d)

Ohm
Answer:

Option (d)

Showing 31 to 40 out of 117 Questions
1 2 3 4 5 6