Question

Assertion :Two charges $-q$ each are fixed at points $A$ and $B$. When a third charge $-q$ is moved from $A$ to $B$, electrical potential energy first decreases, then increases. Reason: Along the line joining $A$ and $B$, the third charge is in stable equilibrium position at centre.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

Electrical potential between two charges is given by $\frac{k{q}_1{q}_2}{r}$

When the charge is at A, the potential is maximum, and tending to infinity because $r\to 0$.

Also when the charge is at B, the potential is maximum, and tending to infinity because $r\to 0$.

In between these points, the potential decreases as one goes from A to B with minimum value at the center where the charge is at equilirbium, and later increases.