A parallel plate capacitor has plate area `25 cm^(2)` and a separation of 2 m m between the plates. The capacitor is connected to a battery of 12 V . Find
The plate separation is decreased to 1 . 0 m m .
Find the extra charge given by the battery to the positive plate.

Explanation

Given, area of plate, `A = 25 cm^(2) = 25 xx 10^(-4) m^(2)`
Distance between the plates, ` d = 2 m m = 2 xx 10^(-3) m` If the plate separation is decreased to half, the capacity becomes twice, then charge becomes twice as battery is still connected
`:.` Extra charge given by the battery = q. - q
= 2 q - q = q
`= 1 . 33 xx 10 ^(-10) C `