Question

An ac generator consists of a coil of 100 turns and cross sectional area of 3m² rotating at a constant angular speed of 60 rad/sec in a uniform magnetic field of 0.04T. The resistance of this coil is 500 ohm. Calculate i) Maximum current drawn from the generator and ii) Maximum power dissipated in the coil.

Answer 1

N = 100 , A = 3m², ω = 60 rad/s

B = 0.4T R = 500Ω

As induced emf is given by= NBAω sinωt

Max emf = e₀ = NBAω = 100 x 0.4 x 3 x 60

= 7200 volt

Induced current (max) I₀ = 7200/500 = 18A

Power = e₀I₀ 7200 x 18 = 1.296 x 10³ watt