Question

The capacity of a parallel plate condenser is `12muF`. Its capacity, when the separation between plates is doubled and area is halved will be
A. `3muF`
B. `12muF`
C. `6muF`
D. `1.5muF`

Answer 1

Correct Answer - A
`C_(1)=12muF, C_(2)=?`
If `d_(2)=2d_(1)andA_(2)=A_(1)/2`
`CpropA/d`
`therefore" "C_(2)/C_(1)=A_(2)/A_(1)xxd_(1)/d_(2)=A_(1)/(2A_(1))xxd_(1)/(2d_(1))=1/4`
`C_(2)=C_(1)/4=12/4=3muF`