Electrostatics Question 431
Question: A charge $ (-q) $ and another charge $ (+Q) $ are kept at two points A and B respectively. Keeping the charge $ (+Q) $ fixed at B, the charge $ (-q) $ at A is moved to another point C such that ABC forms an equilateral triangle of side l. The net work done in moving the charge $ (-q) $ is [MP PET 2001]
Options:
A) $ \frac{1}{4\pi {\varepsilon _{0}}}\frac{Qq}{l} $
B) $ \frac{1}{4\pi {\varepsilon _{0}}}\frac{Qq}{l^{2}} $
C) $ \frac{1}{4\pi {\varepsilon _{0}}}Qql $
D) Zero
Show Answer
Answer:
Correct Answer: D
Solution:
Potential at A and C are equal. Hence work done in moving -q charge from A to C is zero.