A permanent magnet dc commutator motor has a no load speed of 6000 rpm when connected to a 120V dc supply. The armature resistance is 2.5 ohms and other losses may be neglected. The speed of the motor with supply voltage of 60V developing a torque 0.5 Nm, is:

The compensating winding in a dc machine

Ratio of the rotor reactance X to the rotor resistance R for a two-phase servomotor

A three phase, wound rotor induction motor is to be operated with slip energy recovery in the constant torque mode, when it delivers an output power P₀ at slop 's'. then theoretically, the maximum power that is available for recovery at the rotor terminals, is equal to