Question

Metal sphere A has charge of −Q. An identical metal sphere B has charge of + 2Q. The magnitude of electric force on sphere B due to sphere A is F. The magnitude of electric force on sphere A due to sphere B must be:

A. 2FB. F/4C. F/2D. FE. 4F

Answer 1

To solve this problem we will apply the electrostatic Force equations defined from Coulomb's Law. In general, said force can be defined as,

`F = (kq_1q_2)/(r^2)`

Here,

k = Coulomb's constant

`q_(1,2)` = Charge

r = Distance

The electric force in B due to A is

`F = (kQ(-2Q))/(r^2)`

`F = (-2Q^2)/(r^2)`

The force in A due to B is

`F' = (kq_1q_2)/(r^2)`

`F' = (kQ(-2Q))/(r^2)`

`F' = (-2Q^2)/(r^2)`

Therefore they are the same.

`F' = F`

Correct option is D. F.