Question

What is the relation of the rotor resistance with respect to the starting torque?

(a) rotor resistance is indirectly proportional to the starting torque

(b) rotor resistance is directly proportional to the starting torque

(c) rotor resistance is indirectly proportional to the square of the starting torque

(d) rotor resistance is directly proportional to the square of the starting torque

I have been asked this question during an interview for a job.

This intriguing question comes from Design of Rotor Bars and Slots in portion Three Phase Induction Motor of Design of Electrical Machines

Answer 1

Correct option is (b) rotor resistance is directly proportional to the starting torque

Explanation: The rotor resistance is directly proportional to the starting torques. High resistance leads to high starting torque.