Question

A rectangular loop of sides 8 cm and 2 cm is lying in a uniform magnetic field of magnitude 0.5 T with its plane normal to the field. The field is now gradually reduced at the rate of 0.02 T/s. If the resistance of the loop is 1.6 Ω, then find the power dissipated by the loop as heat.

Answer 1

Induced emf, |ε| = \(\frac{dΦ}{dt} = A\frac{dB}{dt}\) = 8 x 2 x 10^-4 x 0.02

ε = 3.2 × 10^-5 V

Induced current, I = \(\frac{ε}{R}\) = 2 × 10^-5 A

Power loss = I²R = 4 × 10^-10 × 1.6 = 6.4 × 10^-10 W