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 number of turns in the primary coil of a transformer is $200$ and the number of turns in the secondary coil is $10$. If $240 \ V$ $AC$ is applied to the primary,the output from the secondary will be......$V$.

In a step-up transformer,the turn ratio is $8:1$. $A$ $60\,Hz, 120\,V$ input is connected to its primary coil. The load resistance in the secondary coil is $10^4\,\Omega$. Find the current in the secondary coil.

The primary winding of a transformer has $500$ turns,whereas its secondary has $5000$ turns. The primary is connected to an $ac$ supply of $20\, V$,$50\, Hz$. The secondary will have an output of

The instrument which works on the principle of mutual inductance is

Large transformers,when used for some time,become hot and are cooled by circulating oil. The heating of a transformer is due to: