Question

The coil of an ac generator consists of 100 turns of wire, each of area 0.5 m². The resistance of the wire is 100 Ω. The coil is rotating in a magnetic field of 0.8 T perpendicular to its axis of rotation, at a constant angular speed of 60 radians per second. Calculate the maximum emf generated and power dissipated in the coil.

Answer 1

Given: N = 100, A = 0.5 m², ω = 60 rad/s

B = 0.8T

R = 100 Ω

As induced emf is given by,

= NBA ω sin ωt

Max emf e₀ = NBAω = `100 xx 0.8 xx 0.5 xx 60`

= 2400 V

Induced current (max)I₀ = `e_0/R`

= `2400/100 = 24` A

Power = `e_0I_0`

= `2400 xx 24 = 5.760 xx 10^4` watt