In a lossless transformer,an alternating current of $2 \ A$ is flowing in the primary coil. The number of turns in the primary and secondary coils are $100$ and $20$ respectively. The value of the current in the secondary coil is.......$A$

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 $A/s$?

Using the equation of power for an ideal transformer,prove $\frac{I_p}{I_s} = \frac{V_s}{V_p} = \frac{N_s}{N_p}$.

The primary and the secondary coils of a transformer contain $10$ and $100$ turns, respectively. The primary coil is connected to a battery that supplies a constant voltage of $1.5 \, V$. The voltage across the secondary coil is .................. $V$.

$A$ power transformer (step-up) with a $1:8$ turn ratio has $60\, Hz, 120\, V$ across the primary; the load in the secondary is $10^4\ \Omega$. The current in the secondary is:

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