A thin circular ring of area `A` is perpendicular to 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 circuit is `R`. When the ring is suddenly squeezed to zero area, the charge flowing through galvanometer is:

Options

A. `(BR)/(A)`
B. `(AB)/(R )`
C. `ABR`
D. `(B^(2)A)/(R^(2)`

Answer

B

Explanation

`Q=(Ndeltaphi)/(R )=(phi_(2)-phi_(1))/(R )=(BA-0)/(R )=(BA)/(R )`