Electric Drives (3160919) MCQs

MCQs of Induction motor characteristics

Showing 11 to 20 out of 63 Questions
1 2 3 4 5 6
11.

A 3-phase 440 V, 50 Hz induction motor has 4% slip. The frequency of rotor current will be

(a)

50 Hz
(b)

25 Hz
(c)

5 Hz
(d)

2 Hz
Answer:

Option (d)

12.

The efficiency of an induction motor is about

(a)

Less than 50%
(b)

100%
(c)

80-90%
(d)

50-60%
Answer:

Option (c)

13.

A 50 Hz, 3-phase induction motor has a full load speed of 1440 r.p.m. The number of poles in the motor is

(a)

2 pole
(b)

4 pole
(c)

6 pole
(d)

8 pole
Answer:

Option (b)

14.

A three phase, 50 Hz induction motor has a full load speed of 1440 rpm. The full load slip will be

(a)

3%
(b)

5%
(c)

4%
(d)

2%
Answer:

Option (c)

15.

If any two phases for an induction motor are interchanged

(a)

The motor will run in the reverse direction
(b)

The motor will continue to run in the same direction
(c)

The motor will stop
(d)

The motor will Burn
Answer:

Option (a)

16.

An induction Motor is

(a)

Self-starting with high torque
(b)

Self-starting with zero torque
(c)

Self-starting with low torque
(d)

Not self-starting
Answer:

Option (c)

17.

At standstill condition the value of slip is

(a)

0
(b)

Infinity
(c)

One
(d)

None of the above
Answer:

Option (c)

18.

An induction motor is analogous to

(a)

Auto-transformer
(b)

Two windings transformer with secondary short circuited
(c)

Two windings transformer with secondary open circuited
(d)

Synchronous motor
Answer:

Option (b)

19.

In induction generator operation the slip is always

(a)

Positive
(b)

Negative
(c)

Infinite
(d)

Zero
Answer:

Option (b)

20.

The rotor power output of a 3-phase induction motor is 30 KW and corresponding slip is 4%. The rotor copper loss will be

(a)

625 Watt
(b)

250 Watt
(c)

1000 Watt
(d)

1250 Watt
Answer:

Option (d)

Showing 11 to 20 out of 63 Questions
1 2 3 4 5 6