Electric Drives (3160919) MCQs

MCQs of Induction motor characteristics

Showing 1 to 10 out of 63 Questions
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1.

When the load is above ………………. a synchronous motor is found to be more economical?

(a)

2 kW
(b)

20 kW
(c)

50 kW
(d)

100 kW
Answer:

Option (d)

2.

Which of the following motors are used for elevators?

(a)

Induction motor
(b)

Synchronous motor
(c)

Capacitor start single phase motor
(d)

Any of these
Answer:

Option (a)

3.

For blowers which of the following motor is preferred?

(a)

D.C. series motor
(b)

D.C. shunt motor
(c)

Squirrel cage induction motor
(d)

Wound rotor induction motor
Answer:

Option (c)

4.

Reluctance motor is a __________________ 

(a)

variable torque motor
(b)

low torque variable speed motor
(c)

self-starting type synchronous motor
(d)

low noise, slow speed motor
Answer:

Option (c)

5.

_____________ method of starting a three phase induction motor needs six terminals.

(a)

 Star-delta
(b)

Resistance starting
(c)

Auto-transformer
(d)

None of the above
Answer:

Option (a)

6.

In which of the following applications variable speed operation is preferred?

(a)

Exhaust fan
(b)

Ceiling fan
(c)

Refrigerator
(d)

Water pump
Answer:

Option (b)

7.

For which of the following applications motor has to start with high acceleration?

(a)

Oil expeller
(b)

Floor Mill
(c)

Lifts and hoists
(d)

Centrifugal pump
Answer:

Option (c)

8.

The cost of an induction motor will increase as

(a)

horsepower rating increases but r.p.m. decreases
(b)

horsepower rating decreases but r.p.m. increases
(c)

horsepower rating and operating speed increases
(d)

horsepower rating and operating speed decreases
Answer:

Option (a)

9.

A wound rotor induction motor is preferred over a squirrel cage induction motor when the major consideration involved is

(a)

High starting Torque
(b)

Low starting current
(c)

Speed control over the limited range
(d)

All of the above 
Answer:

Option (d)

10.

In an induction motor, no-load the slip is generally

(a)

Less than 1%
(b)

5%
(c)

2%
(d)

4%
Answer:

Option (a)

Showing 1 to 10 out of 63 Questions
1 2 3 4 5 6