A 4 pole, 50 Hz IM operates at 7% slip. The frequency of EMF induced in the rotor will be ________.

Correct option is B

$$\text{Given:} \\[4pt]\bullet \; \text{Slip } s = 7\% = 0.07 \\[4pt]\bullet \; \text{Supply frequency } f_s = 50\,\text{Hz} \\[8pt]\text{The frequency of the EMF induced in the rotor is given by:} \\[4pt]f_r = s \times f_s \\[6pt]f_r = \frac{7}{100} \times 50 = 3.5\,\text{Hz}$$​​