$A$ transformer has $100$ turns in the primary coil and carries $8 \, A$ current. If the input power is $1 \, kW$, the number of turns required in the secondary coil to have $500 \, V$ output is:

The quantity that remains unchanged in the output with respect to the input in an ideal transformer is . . . . . . .

If a transformer of an audio amplifier has an output impedance of $8000 \ \Omega$ and the speaker has an input impedance of $8 \ \Omega$,what should be the ratio of the primary to secondary turns of this transformer connected between the amplifier output and the loudspeaker?

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 . . . . . . .

Voltage in the secondary coil of a transformer does not depend upon.

Write important uses of transformer.