$A$ $220\, V$ input is supplied to a transformer. The output circuit draws a current of $2.0\, A$ at $440\, V$. If the efficiency of the transformer is $80\%$,the current drawn by the primary windings of the transformer is ..... $A$.

In a transformer,the number of turns in the primary coil and secondary coil are $5$ and $4$ respectively. If $240 \ V$ is applied to the primary coil,then the ratio of the current in the primary coil to the secondary coil is:

$A$ step-up transformer operates on a $230 \ V$ line and a load current of $2 \ A$. The ratio of primary and secondary windings is $1:25$. Then the current in the primary is (in $A$)

An ideal transformer with a purely resistive load operates at $12\,kV$ on the primary side. It supplies electrical energy to a number of nearby houses at $120\,V$. The average rate of energy consumption in the houses served by the transformer is $60\,kW$. The value of the resistive load $(R_s)$ required in the secondary circuit will be $.........\,m\Omega$.

Which device is used to transmit voltage over large distances and why?

Why is a soft iron core used in a transformer?