Question

A uniformly charged sphere of radius R has charge +Q. A point charge –q is placed at a distance of 2R from the center of the sphere. The point charge will execute the simple harmonic motion. The statement is _____

(a) False

(b) True

This question was posed to me in semester exam.

My doubt stems from Electric Field topic in portion Charges and Fields of Physics – Class 12

Answer 1

Correct option is (a) False

The explanation: In the case of SHM, the force on a body is inversely proportional to the distance of the body from the mean position. But in this case, we know the force acting on the body is inversely proportional to the square of the distance [F =\(\frac {qQ}{4\pi\varepsilon_o(2R)^2}\)]. So the motion of the body will be oscillatory but not SHM.