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

$A$ 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 voltage of an ideal transformer,connected to a $240 \, V$ $a.c.$ mains,is $24 \, V$. When this transformer is used to light a bulb with rating $(24 \, V, 24 \, W)$,calculate the current in the primary coil of the circuit.

$A$ transformer has an efficiency of $80 \%$. The input power to the primary coil is $4 \text{ kW}$ at a voltage of $100 \text{ V}$. If the secondary voltage is $200 \text{ V}$,what are the primary and secondary currents,respectively?

$A$ step-up transformer connected to a $220 \,V$ $AC$ line is to supply $22 \,kV$ for a neon sign in the secondary circuit. In the primary circuit,a fuse wire is connected which is to blow when the current in the secondary circuit exceeds $10 \,mA$. The turns ratio of the transformer is:

In a transformer,the number of turns in the primary coil is $140$ and in the secondary coil is $280$. If the current in the primary coil is $4\,A$,then the current in the secondary coil is.....$A$.