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.....$A$.

$A$ transformer having an efficiency of $90 \%$ is working on a $200 \ V$ and $3 \ kW$ power supply. If the current in the secondary coil is $6 \ A$,the voltage across the secondary coil and the current in the primary coil respectively are:

The primary of a transformer has $100$ turns and operates at $100 \,V - 200 \,W$. The number of turns in the secondary,if the output voltage is $2000 \,V$,is:

The number of turns in the primary and secondary coils of a transformer are $50$ and $200$ respectively. If the current in the primary coil is $4 \,A$, then the current in the secondary coil is: (in $\,A$)

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 $\,A$)?

$A$ step-down transformer is connected to a $2400 \, V$ line, and $80 \, A$ of current is found to flow in the output load. The ratio of the turns in the primary and secondary coil is $20 : 1$. If the transformer efficiency is $100\%$, then the current flowing in the primary coil will be: (in $A$)