Question

Two charged spheres are separated by 2 mm. Which of the following would yield the greatest attractive force?

• A. +2q and -2q
• B. +2q and +2q
• C. -2q and -2q
• D. 1 and -4q

Hint:

The attractive force between charges is greatest when the charges are opposite and have the same magnitude.

Answer 1

The Correct Option is A

The attractive force between two charged spheres is given by Coulomb's law: \[ F = \frac{k |q_1 q_2|}{r^2} \] where: $k$ is Coulomb's constant, $q_1$ and $q_2$ are the charges, and $r$ is the distance between the charges. The force is greatest when the charges are of opposite signs and the charges are equal, as in the case of $+2q$ and $-2q$.