A circular coil of radius 5 cm and 300 turns rotates at 35 rad/s in a 0.05 T field. What is the maximum emf induced?
**AC generator** principle same as rotating coil, N=200 turns A=0.04 m² B=0.1 T f=50 Hz ω=2π×50=314 rad/s, e₀= N B A ω =200×0.1×0.04×314=251.2 V, emf e= e₀ sin ωt, frequency equals rotation frequency, maximum when plane parallel to field. A = π r² = 3.14 × (0.05)² = 0.00785 m² . ε₀ = N B A ω = 300 × 0.05 × 0.00785 × 35 = 4.12375 V ≈ 4.12 V . Using Φ = B A cosθ, e = -N dΦ/dt = -N A dB/dt = B l v = N B A ω sinωt, L = μ₀ N²A/l, M = e/(dI/dt) and U
Ref: NCERT > Physics Book > Electromagnetic Induction > Rotational EMF and AC Generator
