A circular loop of wire with resistance has a radius of

PHYSICS · Subjective · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

A circular loop of wire with resistance

2.0\,\Omega

has a radius of

12\,\text{cm}

. The radius is decreasing at a steady rate of

1.5\,\text{mm}\,/\,\text{s}

while the loop remains in a uniform

0.40\,\text{T}

magnetic field perpendicular to its plane. Determine the power dissipated as thermal energy in the loop at this instant.