Insertion of resistance in the rotor of an induction motor to develop a given torque

Answer: Option A

Inserting resistance into the rotor circuit of an induction motor increases the total impedance of the rotor circuit.

This increased impedance causes the rotor current to decrease for a given torque since current is inversely proportional to impedance.

The purpose of adding resistance is to control the torque and current characteristics during starting or at low speeds.

Therefore, inserting resistance decreases the rotor current, making Option A the correct answer.