Q 12-06-015NEETJEE MainMedium
A metal rod of length $1$ m rotates about one end at $20$ rad/s in a plane perpendicular to a uniform field of $0.5$ T. The emf between its ends is
Answer: (A) $5$ V
Concept. A rod rotating about one end: $\varepsilon = \dfrac12B\omega l^2$.
Step 1. Substitute.
$$\varepsilon = \frac12 \times 0.5 \times 20 \times 1^2 = 5\ \text{V}$$
Answer. $5$ V (Option A).
Solution by Sreeraj P, M.Sc Physics