Q 12-07-141JEE MainJEE Main 2019 (9 Jan, Shift 2)Easy
A power transmission line feeds input power at $2300\ \text{V}$ to a step down transformer with its primary windings having $4000$ turns. The output power is delivered at $230\ \text{V}$ by the transformer. If the current in the primary of the transformer is $5\ \text{A}$ and its efficiency is $90\%$, the output current would be:
Answer: (D) $45\ \text{A}$
Input power $= 2300\times5 = 11500\ \text{W}$; output power $= 0.9\times11500 = 10350\ \text{W}$.
$$I_s = \frac{10350}{230} = 45\ \text{A}$$
Solution by Sreeraj P, M.Sc Physics