Electrostatics Question 55
Question: The distance between the circular plates of a parallel plate condenser $ 40mm $ in diameter, in order to have same capacity as a sphere of radius $ 1\ metre $ is [MP PET 1992]
Options:
A) $ 0.01mm $
B) 0.1 $ mm $
C) 1.0 $ mm $
D) 10 $ mm $
Show Answer
Answer:
Correct Answer: B
Solution:
$ 4\pi {\varepsilon _{0}}r=\frac{{\varepsilon _{0}}A}{d} $
therefore $ d=\frac{A}{4\pi r}=\frac{\pi {{(20\times {{10}^{-3}})}^{2}}}{4\pi \times 1}=0.1mm $
