The ratio of secondary to primary turns in a transformer is $3 : 2$. If the power output is $P$,then the input power,neglecting all losses,must be equal to:

$A$ transformer has a turn ratio of $100/1$. If the secondary coil has a $4 \, A$ current,then the current in the primary coil is......$A$

The quantity that remains unchanged in a transformer is:

In a step-up transformer, the turn ratio is $1 : 2$. A Leclanche cell $(e.m.f. = 1.5 \, V)$ is connected across the primary. The voltage developed in the secondary would be ......... $V$.

$A$ $12\,V, 60\,W$ lamp is connected to the secondary of a step-down transformer, whose primary is connected to $AC$ mains of $220\,V$. Assuming the transformer to be ideal, the current in the primary winding is $..........\,A$.

$A$ transformer is a device which converts