Q 12-06-150NEETNEET 2022Top questionMedium
A big circular coil of $1000$ turns and average radius $10$ m is rotating about its horizontal diameter at $2\ \text{rad s}^{-1}$. If the vertical component of earth's magnetic field at that place is $2 \times 10^{-5}$ T and electrical resistance of the coil is $12.56\ \Omega$, then the maximum induced current in the coil will be
Answer: (D) $1$ A
Rotating about a horizontal diameter, the coil cuts the vertical field component. Peak emf:
$$\varepsilon_0 = NBA\omega = 1000 \times 2 \times 10^{-5} \times \pi(10)^2 \times 2 = 4\pi \approx 12.56\ \text{V}$$
$$I_0 = \frac{\varepsilon_0}{R} = \frac{12.56}{12.56} = 1\ \text{A}$$
Solution by Sreeraj P, M.Sc Physics