In repulsion motor, zero torque is developed when
A)brush axis is 45° electrical to field axis
B)brush axis coincides with the field axis
C)brush axis is 90° electrical to field axis
D)both (b) and (c)

Question

Quizplus · Accepted Answer

In a repulsion motor, zero torque is developed when the brush axis either coincides with the field axis or is 90° electrical to the field axis. This is because, in both positions, the interaction between the magnetic field and the current in the rotor conductors (which is induced due to the brushes' position) does not produce a torque.

In Repulsion Motor, Zero Torque Is Developed When