Electrostatics Question 450
Question: If 3 charges are placed at the vertices of equilateral triangle of charge -q? each. What is the net potential energy, if the side of equilateral $ \Delta $ is l cm [AIEEE 2002]
Options:
A) $ \frac{1}{4\pi {\varepsilon _{0}}}\frac{q^{2}}{l} $
B) $ \frac{1}{4\pi {\varepsilon _{0}}}\frac{2q^{2}}{l} $
C) $ \frac{1}{4\pi {\varepsilon _{0}}}\frac{3q^{2}}{l} $
D) $ \frac{1}{4\pi {\varepsilon _{0}}}\frac{4q^{2}}{l} $
Show Answer
Answer:
Correct Answer: C
Solution:
$ U=\frac{1}{4\pi {\varepsilon _{0}}}.\frac{Q _{1}Q _{2}}{r}; $
net potential energy $ U _{net}=3\times \frac{1}{4\pi {\varepsilon _{0}}}.\frac{q^{2}}{l} $
