A uniform magnetic field B=20 T exists to the right of the boundary in gravity-free space. The shown conducting circular arc of radius 2 cm and total resistance 4 Ω rotates about O with constant angular speed 2 rad s⁻¹. Find the power in µW required to maintain the angular speed from t=π/6 s to t=π/3 s.

Question

G1 Physics · Accepted Answer

For a moving conductor, ε=∫(v⃗×B⃗)·dℓ⃗. Combine this with Ohm’s law and Lenz’s law where required. The result is 16.