In a transformer,the number of turns in primary and secondary are $500$ and $2000$ respectively. If the current in the primary is $48 \ A$,the current in the secondary is......$A$.

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

An ideal transformer has $500$ and $5000$ turns in primary and secondary windings respectively. If the primary coil is connected to a $6\, V$ battery, then the secondary voltage is....$V$

$A$ step-down transformer has a $N_{S}$ to $N_{P}$ ratio of $1: 20$. If $8 \, V$ are developed across a $0.4 \, \Omega$ secondary load, the primary current will be: (in $ \, A$)

$A$ 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 ........ $kW$.

Large transformers,when used for some time,become hot and are cooled by circulating oil. The heating of a transformer is due to: