The ratio of secondary to primary turns is $9:4$. If power input is $P$, what will be the ratio of power output (neglect all losses) to power input?

$A$ 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

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......$V$.

The primary coil of a transformer is connected to a $220 \,V$ $AC$ source. The number of turns in the primary and secondary coils are $100$ and $10$ respectively. The secondary coil is connected to two resistors in series as shown in the figure. The output voltage $\left(V_0\right)$ is: (in $\,V$)

$A$ 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......$A$

$A$ transformer is used to light a $140\, W$, $24\, V$ lamp from a $240\, V$ $AC$ mains. The current in the main cable is $0.7\, A$. The efficiency of the transformer is......$\%$