Electrostatics Question 67
Question: A parallel plate capacitor has a capacity $ C $ . The separation between the plates is doubled and a dielectric medium is introduced between the plates. If the capacity now becomes$ 2C $ , the dielectric constant of the medium is [Haryana CEE 1996]
Options:
A) 2
B) 1
C) 4
D) 8
Show Answer
Answer:
Correct Answer: C
Solution:
$ C _{1}={\varepsilon _{0}}\frac{A}{d _{1}} $ and $ C _{2}=K{\varepsilon _{0}}\frac{A}{d _{2}} $ $ \frac{C _{1}}{C _{2}}=\frac{1}{K}\times \frac{d _{2}}{d _{1}} $
$ =\frac{C}{2C}=\frac{1}{K}\times \frac{2d}{d} $
therefore K = 4
