$A$ transformer works on

$A$ transformer is used to light a $100 \,W-110 \,V$ lamp from a $220 \,V$ mains. If the main current is $0.5 \,A$, the efficiency of the transformer is: (in $\%$)

Voltage in the secondary coil of a transformer does not depend upon.

The turn ratio of a transformer is given as $2 : 3$. If the current through the primary coil is $3 \, A$,calculate the current through the load resistance (secondary coil). (in $, A$)

The primary coil of a transformer is connected to a $220 \,V$ $AC$ source. The number of turns in the primary and secondary coils are $100$ and $10$ respectively. The secondary coil is connected to two resistors in series as shown in the figure. The output voltage $\left(V_0\right)$ is: (in $\,V$)

In an ideal step-up transformer,the number of turns in the primary coil and secondary coil are $100$ and $200$ respectively. If the output current is found to be $5 \text{ A}$,then the input current will be . . . . . . . (in $\text{ A}$)