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:

In a transformer,the number of turns in the primary coil and secondary coil are $5$ and $4$ respectively. If $240 \ V$ is applied to the primary coil,then the ratio of the current in the primary coil to the secondary coil is:

$A$ step-down transformer is used to reduce the main supply from $V_1$ volt to $V_2$ volt. The primary coil draws a current $I_1$ $A$ and the secondary coil draws $I_2$ $A$. $(I_1 < I_2)$. The ratio of input power to output power is

$A$ $60\, W$ load is connected to the secondary of a transformer whose primary draws line voltage. If a current of $0.54\, A$ flows in the load,what is the current in the primary coil? Comment on the type of transformer being used.

In an ideal step-up transformer,if the input voltage and input power are $V_1$ and $P_1$ respectively,and the output voltage and output power are $V_2$ and $P_2$ respectively,then

$A$ power transmission line feeds input power at $2300\,V$ to a step-down transformer with its primary windings having $4000$ turns,giving the output power at $230\,V.$ If the current in the primary of the transformer is $5\,A,$ and its efficiency is $90\%,$ the output current would be......$A$