The self-inductance of two coils of a transformer is $20 mH$ and $30 mH$. What is the resistance between them?

$A$ transformer with efficiency $80\%$ works at $4\, kW$ and $100\, V$. If the secondary voltage is $200\, V$, then the primary and secondary currents are respectively:

$A$ power transmission line feeds input power at $2300 \ V$ to a step-down transformer with its primary winding having $4000$ turns. What should be the number of turns in the secondary in order to get output power at $230 \ V$?

$A$ 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......$A$

In a step-up transformer,if the ratio of turns of primary to secondary is $1:10$ and the primary voltage is $230 \, V$. If the load current is $2 \, A$,then the current in the primary is.......$A$.

$A$ 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......$A$.