Electrostatics Question 210
Question: Two point charges placed at a certain distance r in air exert a force F on each other. Then the distance r’ at which these charges will exert the same force in a medium of dielectric constant k is given by [EAMCET 1990; MP PMT 2001]
Options:
A) r
B) r/k
C) $ r/\sqrt{k} $
D) $ r\sqrt{k} $
Show Answer
Answer:
Correct Answer: C
Solution:
$ F=F’ $ or $ \frac{Q _{1}Q _{2}}{4\pi {\varepsilon _{0}}r^{2}}=\frac{Q _{1}Q _{2}}{4\pi {\varepsilon _{0}}r{{’}^{2}}K}\Rightarrow r’=\frac{r}{\sqrt{K}} $
