The instrument which works on the principle of mutual inductance is

$A$ current of $5 \,A$ is flowing at $220 \,V$ in the primary coil of a transformer. If the voltage produced in the secondary coil is $2200 \,V$ and $50 \%$ of power is lost, then the current in the secondary will be (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-up transformer operates on a $230\, V$ line and supplies a load of $2\, A$. The ratio of the primary and secondary windings is $1 : 25$. The current in the primary is.... (in $, A$)

$A$ step-up transformer operates on a $230 \ V$ line and a load current of $2 \ A$. The ratio of primary and secondary windings is $1:25$. Then the current in the primary is (in $A$)

$A$ step-down transformer reduces the voltage of a transmission line from $2200 \,V$ to $220 \,V$. The power delivered by it is $880 \,W$ and its efficiency is $88 \%$. The input current is