$A$ 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......$\%$

In a transformer,the primary has $500$ turns and the secondary has $50$ turns. If $100 \ V$ is applied to the primary coil,the voltage developed in the secondary will be.....$V$

$A$ power transformer (step-up) with a $1:8$ turn ratio has $60\, Hz, 120\, V$ across the primary; the load in the secondary is $10^4\ \Omega$. The current in the secondary is:

What is a transformer? Write its principle and describe its construction.

$A$ transformer connected to a $220 \, V$ line shows an output of $2 \, A$ at $11000 \, V$. The efficiency is $100 \%$. The current drawn from the line is ...... $A$.

$A$ transformer with a turns ratio $\frac{N_{1}}{N_{2}} = \frac{50}{1}$ is connected to a $120 \ V$ $AC$ supply. If the primary and secondary circuit resistances are $1.5 \ k\Omega$ and $1 \ \Omega$ respectively,find the power output (in $W$).