$A$ transformer is employed to reduce $220\, V$ to $11\, V$. The primary draws a current of $5\, A$ and the secondary $90\, A$. The efficiency of the transformer is......$\%$

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

The output power in a step-up transformer used in practice is . . . . . .

$A$ step-up transformer has a transformation ratio of $3:2$. What is the voltage in the secondary coil if the voltage in the primary coil is $30\, V$?

$A$ transformer having efficiency $90 \%$ is working on $200 \ V$ and $3 \ kW$ power supply. If the current in the secondary coil is $6 \ A$, the voltage across the secondary coil and the current in the primary coil are respectively:

In a step-up transformer,if the ratio of turns of primary to secondary is $1:10$ and the primary voltage is $230 \, V$. If the load current is $2 \, A$,then the current in the primary is.......$A$.