JEE Main 2026 — 23 January, Evening Shift — Question 38

EMF induced $\varepsilon=\mathrm{A} \frac{\mathrm{dB}}{\mathrm{dt}}=\mathrm{A} \mu_{0} \mathrm{n} \frac{\mathrm{di}}{\mathrm{dt}}$ $\varepsilon=\mathrm{A} \mu_{0} \mathrm{n} \mathrm{i}_{0} \omega \cos \omega \mathrm{t}$ current induced $\mathrm{i}=\frac{\varepsilon}{\mathrm{R}}=\frac{\pi \mathrm{r}^{2} \mu_{0} \mathrm{ni}_{0} \omega}{\mathrm{R}} \cos \omega \mathrm{t}$ So $i=\frac{\pi r^{2} \mu_{0} n i_{0} \omega}{\sqrt{2} R}$ $=\frac{\pi \times 10^{-4} \times 4 \pi \times 10^{-7} \times 500 \times 10 \times 10^{3}}{\sqrt{2} \times 10}$ $=\frac{20 \pi^{2}}{\sqrt{2}} \times 10^{-6}$ $\simeq \frac{197}{\sqrt{2}} \mu \mathrm{~A}$