Question

A charged particle q is shot towards another charged particle Q, which is fixed, with a speed v.It approaches Q upto a closest distance r and then returns. If q were given a speed of 2v the closest distance of approach would be?

r

2r

r/2

r/4

Answer 1

As per formula
V^2 is inversely proportional to radius/closest approach. Hence the second time closest approach is r/4.