$A$ motor starter:

$A$ 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

Assertion : An electric motor will have maximum efficiency when back $emf$ becomes equal to half of applied $emf$.
Reason : Efficiency of electric motor depends only on magnitude of back $emf$.

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 $AC$ generator consists of a coil of $500$ turns and area $2\ m^2$ rotating at an angular speed of $30\ rad\ s^{-1}$ in a uniform magnetic field $B = 0.20\ T$ between two fixed pole pieces. The resistance of the circuit including that of the coil is $1000\ \Omega$. What is the maximum current drawn from the generator?

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 $\Omega$?