The ratio of secondary to primary turns in a transformer is $3 : 2$. If the power output is $P$,then the input power,neglecting all losses,must be equal to:

$A$ transformer having efficiency $90 \%$ is working on $200 \ V$ 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 are respectively:

$A$ transformer connected to a $220 \, V$ line shows an output of $2 \, A$ at $11000 \, V$. The efficiency is $100 \%$. The current drawn from the line is ...... $A$.

In a step-up transformer,the transformation ratio is $4:1$. If a Leclanche cell having an $EMF$ of $1.5 \ V$ is connected to the primary coil of the transformer,then the voltage obtained across its secondary coil is . . . . . . .

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

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