Q 12-07-047JEE MainJEE Main 2024 (1 Feb, Shift 2)Easy
A transformer has an efficiency of $80\%$ and works at $10\ \text{V}$ and $4\ \text{kW}$. If the secondary voltage is $240\ \text{V}$, then the current in the secondary coil is
Answer: (B) $13.33\ \text{A}$
$$P_{out} = 0.8\times4000 = 3200\ \text{W},\qquad I_s = \frac{3200}{240} = 13.33\ \text{A}$$
Solution by Sreeraj P, M.Sc Physics