Question

Choose the correct answer from the following:
If three charged particles are collinear and are in equilibrium, then:

• A. all the charged particles have equal charge.
• B. all the charged particles have the same sign and the distances between two consecutive charged particles are same.
• C. all the charged particles have the same sign
• D. all the charged particles cannot have the same sign

Hint:

In equilibrium problems involving charges, always consider the direction and nature (attractive or repulsive) of electrostatic forces.

Answer 1

The Correct Option is D

If three charged particles are collinear and in equilibrium, the net force on each particle must be zero. This is only possible if the forces from the other two charges cancel out. For this to happen, at least one of the charges must have an opposite sign, so that attractive and repulsive forces can balance. Hence, all particles cannot have the same sign.