Q95 / 120 · VITEEE 2017 · Physics
The current in a coil of $\mathrm{L}=40 \mathrm{mH}$ is to be increased uniformly from 1 A to $11 \mathrm{~A}$ in 4 milli sec. The induced e.m.f. will be
- Correct answerA$100 \mathrm{~V}$
- B$0.4 \mathrm{~V}$
- C$440 \mathrm{~V}$
- D$40 \mathrm{~V}$
Solution
$\mathrm{e}=\frac{\mathrm{LdI}}{\mathrm{dt}}=\frac{40 \times 10^{-3}(11-1)}{4 \times 10^{-3}}=100 \mathrm{~V}$
Hence, the correct answer is option: 'A'.