A 4-pole, lap-connected, separately excited dc motor is drawing a steady current of 40 A while running at 600rpm. A good approximation for the waveshape of the current in an armature conductor of the motor is given by

Figure shows the extended view of a 2 pole dc machine with 10 armature conductors. Normal brush positions are shown by A and B, placed at the inter-polar axis. If the brushes are now shifted, in the direction of rotation, to A' and B' as shown, the voltage waveform  will resemble

The following motor definitely has a permanent magnet rotor

The compensating winding in a dc machine

A 4-pole lap-wound DC generator has a developed power of P watts and voltage of E volts. Two adjacent brushes of the machine are removed as they are worn out. If the machine operates with the remaining brushes, the developed voltage and power that can be obtained from the machine are

A 200V, 10kW lap-wound DC generator has 10 poles and 500 conductors on its armature. If the pole face covers 80% of the pole pitch, the pole face conductors required to fully compensate for armature reaction will be…. conductors/pole.

A 4 pole generator with 16 coil has a two layer lap winding. The pole pitch is

Match the windings of a large D.C series motor and their functions: