The efficiency of a transformer is very high because

The primary winding of a transformer has $500$ turns,whereas its secondary has $5000$ turns. The primary is connected to an $ac$ supply of $20\, V$,$50\, Hz$. The secondary will have an output of

$A$ power transmission line feeds input power at $2300 \, V$ to a step-down transformer with its primary windings having $4000$ turns. The output power is delivered at $230 \, V$ by the transformer. If the current in the primary of the transformer is $5 \, A$ and its efficiency is $90 \%$,the output current would be......$A$.

$A$ 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:

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 $\,A$)?

An $AC$ source of internal resistance $10^3 \Omega$ is connected to a transformer. The ratio of the number of turns in the primary to the number of turns in the secondary to match the source to a load resistance of $10 \Omega$ is