Question

Which is the incorrect regarding equilibrium of the system of three charges?

• A. the three charges must be collinear
• B. the three charges must not be of same sign
• C. the three charges must not be of same magnitude
• D. the equilibrium will always be stable in nature

Answer 1

The correct option is D the equilibrium will always be stable in nature

If three charged particles are in equilibrium under their electrostatic forces, then
(a) The particles must be colinear.
(b) all the charges can not have the same magnitude.
(c) All the charges can not have here same sign.

If the system of three charges is in equilibrium, the equilibrium will always be unstable in nature. It can be explained with a given figure.

Let's consider figure $\text{(I)}$ and $\text{(II)}$ are in equilibrium. It means each charges of the system experiencing zero net force.

Now if any charge of the above system displace by a small distance, all charges start experiencing some net force instantly. Due to net unbalanced force, the system get disturbed, and charges loses their equilibrium position permanently.

Hence, option $\left(d\right)$ is correct.