A vertical conducting ring of radius R falls vertically with a speed V in a horizontal uniform magnetic field B which is perpendicular to the plane of the ring. Which of the following statements is correct

When the ring falls vertically, there will be an induced emf across A and B (e = Bv(2r)). Note that there will be a Potential difference across any two Points on the ring, and the line joining these has a projected length in the horizontal plane. For example, between points P and Q there is a projected length x in the horizontal plane.∴  P.D. across P and Q is          V=BvxBut for points C and D, x = 0Therefore, P.D. = 0Hence (b)