In an ideal transformer, can power increase or decrease? State whether this statement is true or false.

$A$ transformer has $120$ turns in the primary coil and carries $5 \text{ A}$ current. Input power is $1 \text{ kW}$. To have $560 \text{ V}$ output, the number of turns in the secondary coil will be:

$A$ power transmission line feeds input power at $2.3 \text{ kV}$ to a step-down transformer with its primary winding having $3000$ turns. The output power is delivered at $230 \text{ V}$ by the transformer. The current in the primary of the transformer is $5 \text{ A}$ and its efficiency is $90 \%$. The winding of the transformer is made of copper. The output current of the transformer is . . . . . . $A$.

An ideal transformer is used to step up an alternating e.m.f. of $220 \,V$ to $4.4 \,kV$ to transmit $6.6 \,kW$ of power. The primary coil has $100$ turns. What is the current rating of the secondary coil (in $\,A$)?

The alternating voltage induced in the secondary coil of a transformer is mainly due to

$A$ transformer is used to light a $100\,W$ and $110\,V$ lamp from a $220\,V$ main. If the main current is $0.5\,A$, the efficiency of the transformer is approximately .....$\%$