A 3-φ, 50 Hz, 6 pole induction motor has a slip of 3%. What will be the speed of the motor?

Question

Question

This question was previously asked in

MPPGCL JE Electrical 19 March 2019 Shift 2 Official Paper

Answer 1

Concept

The speed of a 3ϕ induction motor is given by:

\(N_r={120f\over P}(1-s)\)

where, s = Slip

Nr = Motor speed

f = Frequency

P = No. of poles

Calculation

Given, s = 3% = 0.03

f = 50 Hz

P = 6

\(N_r={120\times 50\over 6}(1-0.03)\)

Nr = 970 rpm