A circular copper-ring of radius r travels in its plane with a constant velocity v . A uniform magnetic field B is present in the space, directed perpendicular to the plane of the ring. Considering various pairs of diametrically opposite points on the ring, between which pair of points is the emf maximum, and what is the value of this maximum emf?

Step-by-step solution

The motional emf induced between any two points A and B of a conductor moving with velocity v in a uniform magnetic field B is given by = ( v B ) l , where l is the displacement vector from A to B. Let the velocity of the ring be v = v i and the magnetic field be B = B k . The cross product is v B = (v i ) (B k ) = -vB j . The induced emf is = -vB j l . For the magnitude of to be maximum, the displacement vector l must be parallel to the y-axis, which means it must be perpendicular to the velocity v . For diametric