$A$ step-up transformer has a turns ratio of $10:1$. $A$ cell of $e.m.f. = 5 \, V$ is connected to the primary coil. What is the secondary voltage developed?

$A$ transformer is used to light a $100\,W$ and $110\,V$ lamp from a $220\,V$ main. If the main current is $0.5\,A$, the efficiency of the transformer is approximately .....$\%$

The core of a transformer is made up of:

$A$ transformer has $100$ turns in the primary coil and carries $8$ $A$ current. If input power is $1$ $kW$, the number of turns in the secondary coil to have $500$ $V$ output will be

In a transformer,the number of turns in primary and secondary are $500$ and $2000$ respectively. If the current in the primary is $48 \ A$,the current in the secondary is......$A$.

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