Question

A charge ‘q’ is moving towards the centre of an earthed conducting sphere of radius ‘b’ with uniform velocity ‘v’. Distance of two points A and B from the centre of sphere are ‘3a’ and ‘2a’. Conducting sphere is earthed with an ammeter and resistance in series as shown Heat energy produced in the resistance till the point charge moves from A to B is

• A. $\frac{19q^2{b}^{2}vR}{648a^3}$
• B. $\frac{2q^2{b}^{2}vR}{5a^3}$
• C. $\frac{5q^2{b}^{2}vR}{72a^3}$
• D. $Zero$

Answer 1

The correct option is A $\frac{19q^2{b}^{2}vR}{648a^3}$

$V_1+V_2=0,\frac{kq}{x}=\frac{k{q}^{\prime }}{b}$
$\frac{kq}{x^2}=\frac{ki}{b}$
$H=\int i^{2}Rdt$