$A$ transformer is used to light a $140\, W$, $24\, V$ lamp from a $240\, V$ $AC$ mains. The current in the main cable is $0.7\, A$. The efficiency of the transformer is......$\%$

In an ideal step-down transformer, out of the following quantities, which quantity increases in the secondary coil?

$A$ 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 $W$).

$A$ step-down transformer converts transmission line voltage from $11000 \, V$ to $220 \, V$. The primary of the transformer has $6000 \, \text{turns}$ and the efficiency of the transformer is $60 \%$. If the output power is $9 \, kW$, then the input power will be ........ $kW$.

$A$ step-down transformer connected to an $AC$ mains supply of $220 \, V$ is made to operate a $11 \, V, 44 \, W$ lamp. Ignoring power losses in the transformer,what is the current in the primary circuit? (In $A$)

$A$ current of $5 \text{ A}$ is flowing at $220 \text{ V}$ in a primary coil of a transformer. If the voltage produced in the secondary coil is $2200 \text{ V}$ and $50 \%$ of power is lost, then the current in the secondary coil will be (in $\text{ A}$)