The function of an electric motor is:

$A$ motor having an armature of resistance $2\,\Omega$ is designed to operate at $220\,V$ mains. At full speed,it develops a back $e.m.f.$ of $210\,V$. When the motor is running at full speed,the current in the armature is: (in $,A$)

$A$ device which converts electrical energy into mechanical energy is

$A$ generator has an armature resistance of $0.1 \, \Omega$ and develops an induced emf of $120 \, V$ when driven at its rated speed. Its terminal voltage when a current of $50 \, A$ is being drawn is ................. $V$.

An electric motor operating on a $60\, V$ $dc$ supply draws a current of $10\, A$. If the efficiency of the motor is $50\%$,the resistance of its winding is.....$\Omega $

An electric fan operates on the principle of which of the following?