There is an air filled 1pF parallel plate capacitor. When the plate separation is doubled and the space is filled with wax, the capacitance increases to 2pF. The dielectric constant of wax is

Options

A. 2
B. 4
C. 6
D. 8

Answer

B

Explanation

`d. =2d,C. =2pF`
`C=1 pF`
`C=(Aepsilon_0)/d implies 1 xx10^(-12)=(Aepsilon_0)/d`
`C.=(Aepsilon_0k)/(2d) implies 2 xx10^(-12)=(Aepsilon_0k)/(2d)`
`implies 1/(2) =1/(k//2) =2/k`
`implies k = 4`