Question

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

• A. $A$ and $B$ are at the same potential
• B. $C$ and $D$ are at the same potential
• C. current flows in clockwise direction
• D. current flows in anticlockwise direction

Answer 1

The correct option is B $C$ and $D$ are at the same potential

$EMF={\int }_0^{\varphi }Bvrd\theta \left(sin\theta \right)$
where $\theta =0$ at D
Integrating
$V_{\theta }-V_D=Bvr(1-cos\theta )$
$V_A=V_D+BvR$
$V_C=V_D$
(Also can be seen by symmetry)