Physics

Problem

A thin circular ring of area

A

is held perpendicular to a uniform magnetic field of induction

B

. A small cut is made in the ring and a galvanometer is connected across the ends such that the total resistance of the circuit is

R

. When the ring is suddenly squeezed to zero area, the charge flowing through the galvanometer is [1995S] a.

\frac{BR}{A}

\frac{AB}{R}

ABR

\frac{B^2 A}{R^2}