Electrodynamics → Electromagnetic Induction: Problem 1

A metal disc...

A metal disc of radius R = x₁ cm rotates with a constant angular velocity ω = x₂ rad/s about its axis. Find the potential difference between the centre and the rim of the disc if

(a) the external magnetic field is absent;

(b) the external uniform magnetic field B = x₃ mT is directed perpendicular to the disc.