In an $AC$ generator,the ends of the coil are connected to

The armature of a generator of resistance $1 \,\Omega$ is rotated at its rated speed and produces $125 \,V$ without load and $115 \,V$ with full load. The current in the armature coil is ......... $A$.

$A$ rectangular coil of a simple $A.C.$ generator rotates about one of its diameters with a constant angular frequency in the presence of a uniform magnetic field. The direction of the induced current reverses for the third time after how many rotations of the coil?

$A$ motor operating on $100 \ V$ draws a current of $1 \ A$. If the efficiency of the motor is $91.6 \%$,then the loss of power in units of $cal/s$ is

An electric motor operates on a $50\,V$ supply and a current of $12\,A$. If the efficiency of the motor is $30\%$,what is the resistance of the winding of the motor in $\Omega$?

The back emf in a $DC$ motor is maximum when,