In a dc machine the sparking between brushes and commutator surface may be due to
Any of the above
In a dc machine the sparking between brushes and commutator surface may be due to Under commutation, Over commutation and Too raid reversal of current.
Torque developed in an electromechanical energy conversion device depends upon
In electromechanical energy conversion devices (e.g generators and motors) a small air gap is left between the stator and the rotor in order to