In a transformer,the number of turns in the primary coil is $140$ and in the secondary coil is $280$. If the current in the primary coil is $4\,A$,then the current in the secondary coil is.....$A$.

$A$ transformer has $20$ turns in the primary and $100$ turns in the secondary coil. An $AC$ voltage of $V_{\text{in}} = 600 \sin 314t$ is applied to the primary terminal of the transformer. The maximum value of the secondary output voltage obtained in volts is:

$A$ 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:

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

$A$ 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 $\%$)

$A$ transformer has a turn ratio of $100/1$. If the secondary coil has a $4 \, A$ current,then the current in the primary coil is......$A$