Topic: Electrical Machines
The rotor current frequency in an induction motor operating at 50 Hz, with 4% slip is
- A. 48 Hz
- B. 4 Hz
- C. 2 Hz
- D. 16 Hz
Answer: C. 2 Hz
Explanation: The frequency of the rotor current ($f_r$) in an induction motor is the product of the slip ($s$) and the supply frequency ($f$).
Given supply frequency $f = 50$ Hz and slip $s = 4\% = 0.04$.
$f_r = s \times f = 0.04 \times 50 = 2$ Hz.