$A$ $100\%$ efficient transformer has $100$ turns in the primary and $25$ turns in its secondary coil. If the current in the secondary coil is $4 \text{ A}$, then the current in the primary coil is ... $ \text{A}$

In an ideal transformer,the turns ratio is $\frac{N_p}{N_S} = \frac{1}{2}$. The ratio $V_s : V_p$ is equal to (the symbols carry their usual meaning):

$A$ step-up transformer operates on a $220 \,V$ line and supplies $2.2 \,A$. The ratio of primary to secondary winding turns is $11:50$. The output voltage in the secondary is .......... $V$.

$A$ $220 V$ input is supplied to a transformer. The output circuit draws a current of $2.0 A$ at $440 V$. If the ratio of output to input power is $0.8$,then the current drawn by the primary winding is: (in $A$)

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 ......... $V$.

The primary and the secondary coils of a transformer contain $10$ and $100$ turns, respectively. The primary coil is connected to a battery that supplies a constant voltage of $1.5 \, V$. The voltage across the secondary coil is .................. $V$.