$A$ transformer consists of $500$ turns in the primary coil and $10$ turns in the secondary coil with a load of $10\, \Omega$. Find the current in the primary coil when the voltage across the secondary coil is $50\, V$. (in $A$)

For a transformer,the turns ratio is $3$ and its efficiency is $0.75$. The current flowing in the primary coil is $2 \,A$ and the voltage applied to it is $100 \,V$. Then the voltage and the current flowing in the secondary coil are ... respectively.

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

In a transformer,the mutual inductance between the primary and secondary coils is $0.5 \ H$. The resistances of the primary and secondary coils are $20 \ \Omega$ and $5 \ \Omega$ respectively. To induce a current of $0.4 \ A$ in the secondary coil,what is the required rate of change of current in the primary coil in $A/s$?

$A$ generator produces a current of $100 \, A$ at $4000 \, V$. The voltage is stepped up to $2 \times 10^5 \, V$ by a transformer before being sent on a high voltage transmission line of resistance $50 \, \Omega$. The percentage of power loss in the transmission line is (in $\%$)

$A$ step-down transformer has a turns ratio of $20:1$. If $8 \, V$ is applied across a $0.4 \, \Omega$ secondary coil, then the primary current will be: (in $ \, A$)