speed ratio

A 250 V dc shunt machine has armature circuit resistance of 0.6 $$\Omega$$ and field circuit resistance of 125 $$\Omega$$. The machine is connected to 250 V supply mains. The motor...

A $$220V$$ $$DC$$ machine supplies $$20$$ $$A$$ at $$200V$$ as a generator. The armature resistance is $$0.2$$ ohm. If the machine is now operated as a motor at same terminal volta...

The field coil of a two-pole $$d.c.$$ series motor is made up of two identical sections In one case $$(i)$$ of two sections of the field coil are connected in series, and in anothe...