Question

A vertical ring of radius r and resistance R falls vertically. It is in contact with two vertical rails which are joined at the top. The rails are without friction and resistance. There is a horizontal uniform magnetic field of magnitude B perpendicular to the plane of the ring and the rails. When the speed of the ring is v, the current in the section PQ is-

• A. Zero
• B. $\frac{2Brv}{R}$
• C. $\frac{4Brv}{R}$
• D. $\frac{8Brv}{R}$

Answer 1

Answer: (D)

$\frac{8Brv}{R}$

Answer 2

C discharges through (R + R) in series.