Question

Two identical charged spheres suspended from a common point by two massless strings of length l are initially a distance d(d < < l) apart because of their mutual repulsion. The charge begins to leak from both the spheres at a constant rate. As a result the charges approach each other with a velocity υ. Then as a function of distance x between them

(a) υ ∝ x^–1/2 

(b) υ ∝ x^–1

(c) υ ∝ x^1/2 

(d) υ ∝ x

Answer 1

(a) : Figure shows equilibrium positions of the two-sphere.

When charge begins to leak from both the spheres at a constant rate, then