One very small uniformly charged plastic ball is located directly above another such charge in a test tube as shown in the figure.The balls are in equilibrium a distance d apart.If the charge on each ball is doubled,the distance between the balls in the test tube would become

Question

Quizplus · Accepted Answer

The force between two point charges is given by Coulomb's law: F = kq1q2/r^2, where k is a constant, q1 and q2 are the charges, and r is the distance between them.

In this case, since both charges are the same, the force is repulsive. Therefore, if we double the charge on each ball, the force between them will increase by a factor of 4 (since F ∝ q1q2). In order to maintain equilibrium, the distance between the balls must increase by a factor of 2 (since F ∝ 1/r^2). Therefore, the new distance between the balls will be 2d.

Therefore, the correct answer is B) 2d.

One Very Small Uniformly Charged Plastic Ball Is Located Directly