$A$ step-down transformer has a turns ratio of $20:1$. If $8 \, V$ is applied across a $0.4 \, \Omega$ secondary coil, then the primary current will be: (in $ \, A$)

An ideal transformer has $100$ turns in the primary and $250$ turns in the secondary. The peak value of the $ac$ input voltage is $28 \, V$. The r.m.s. secondary voltage is nearest to.....$V$

In a lossless transformer,an alternating current of $2 \ A$ is flowing in the primary coil. The number of turns in the primary and secondary coils are $100$ and $20$ respectively. The value of the current in the secondary coil is.......$A$

An $80 \text{ W}$ lamp is connected to the secondary of a step-down transformer, where the primary is connected to an $AC$ mains of $220 \text{ V}$. Assuming the transformer to be ideal, the current in the primary winding is nearly: (in $\text{ A}$)

$A$ transformer has $20$ turns in the primary and $100$ turns in the secondary coil. An $AC$ voltage of $V_{\text{in}} = 600 \sin 314t$ is applied to the primary terminal of the transformer. The maximum value of the secondary output voltage obtained in volts is:

Write important uses of transformer.