The number of turns in the primary coil of a transformer is $200$ and the number of turns in the secondary coil is $10$. If $240 \ V$ $AC$ is applied to the primary,the output from the secondary will be......$V$.

$A$ transformer has an efficiency of $80 \%$ and works at $10 \ V$ and $4 \ kW$. If the secondary voltage is $240 \ V$, then the current in the secondary coil is: (in $A$)

$A$ 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:

An ideal transformer with a purely resistive load operates at $12\,kV$ on the primary side. It supplies electrical energy to a number of nearby houses at $120\,V$. The average rate of energy consumption in the houses served by the transformer is $60\,kW$. The value of the resistive load $(R_s)$ required in the secondary circuit will be $.........\,m\Omega$.

The quantity that remains unchanged in a transformer is:

The primary of a transformer has $100$ turns and operates at $100 \,V - 200 \,W$. The number of turns in the secondary,if the output voltage is $2000 \,V$,is: