### MCQs of Induction motor characteristics

Showing 21 to 30 out of 63 Questions
21.

In an induction motor if the air gap is increased than which of the following statement is correct

 (a) Power factor will decrease (b) Power factor will increase (c) Speed will increase (d) Speed will decrease
22.

what is the ratio of rotor input power to rotor copper loss in an induction motor?

 (a) 1/(1 – S) (b) 1 – S (c) 1/S (d) S
23.

If an induction machine is run at above the synchronous speed it acts as

 (a) Synchronous Motor (b) Synchronous Generator (c) Induction Generator (d) None of the above
24.

Induction motors have the advantage of

 (a) Less Maintenace (b) Less cost (c) Simple in construction (d) All of the above
25.

An 8 pole, three phase induction motor is supplied from 50 Hz, a.c. supply. On full load, the frequency of induced  EMF in the rotor is 2 Hz. Then the full load slip and the corresponding speed.

 (a) 4% & 750 (b) 4% & 720 (c) 5% & 1000 (d) 5% & 1500
26.

A 4 pole, 3 phase, 50 Hz induction motor runs at a speed of 1470 r.p.m. speed. Then the frequency of the induced e.m.f. in the rotor under this condition

 (a) 1 Hz (b) 2 Hz (c) 5 Hz (d) 6 Hz
27.

The direction of rotation of 3-Φ induction motor is clockwise when it is supplied with the 3-Φ sinusoidal voltage having phase sequence of A-B-C. For counterclockwise rotation, the phase sequence of the power supply should be

 (a) B-C-A (b) A-C-B (c) C-A-B (d) Any of the above
28.

The rotor winding of a 3-phase wound rotor induction motor is generally _____________ connected.

 (a) Delta (b) Star (c) Partially Delta & Partially Star (d) None of the above
29.

An eight-pole wound rotor induction motor operating on 60 Hz supply is driven at 1800 rpm by a prime mover in the opposite direction of revolving magnetic field. The frequency of rotor current is

 (a) 120 Hz (b) 180 Hz (c) 60 Hz (d) 200 Hz
30.

The torque characteristic of a 3-phase induction motor is similar to that of

 (a) DC series Motor (b) DC Shunt Motor (c) DC differentially compound motor (d) DC cumulatively compounded Motor
Showing 21 to 30 out of 63 Questions