Electrostatics Question 177
Question: Three equal charges are placed on the three corners of a square. If the force between $ q _{1} $ and $ q _{2} $ is $ F _{12} $ and that between $ q _{1} $ and $ q _{3} $ is $ F _{13} $ , the ratio of magnitudes $ \frac{F _{12}}{F _{13}} $ is [MP PET 1993]
Options:
A) $ 1/2 $
B) 2
C) $ 1/\sqrt{2} $
D) $ \sqrt{2} $
Show Answer
Answer:
Correct Answer: B
Solution:
$ F _{12}=\frac{1}{4\pi {\varepsilon _{0}}}\cdot \frac{q^{2}}{a^{2}} $ and $ F _{13}=\frac{1}{4\pi {\varepsilon _{0}}}\cdot \frac{q^{2}}{{{(a\sqrt{2})}^{2}}} $
therefore $ \frac{F _{12}}{F _{13}}=2 $
