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

Solution (By Examveda Team)

The slip in an induction motor is the difference between the synchronous speed and the actual rotor speed, expressed as a percentage of the synchronous speed. The frequency of the rotor emf is related to the slip and the supply frequency. For a 3-phase induction motor:

Supply Frequency (f_s): 50 Hz
Slip (s): 4% or 0.04
The frequency of the rotor emf (f_r) can be calculated using the formula:

f_r = s × f_s

Substituting the values:

f_r = 0.04 × 50 Hz = 2 Hz

Therefore, the frequency of the rotor emf is 2 Hz.