A parallel-plate capacitor in which the plates are extendable is connected to a
ID: 1319255 • Letter: A
Question
A parallel-plate capacitor in which the plates are extendable is connected to a battery and charged until there is a charge +q on one plate and a charge ?q on the other plate.
With the battery still connected, the area of each plate is tripled by sliding the extension. How much charge is on each plate now?
In which case, before the plate area is changed or after, is more force required to keep the plates apart?
In which case, before the plate area is changed or after, is more force required to keep the plates apart?
After the plate area is changed. The force required to keep the plates apart does not change. Before the plate area is changed.Explanation / Answer
Capacitance
C=Ae/d
when area is tripled
C=3Ae/d
Q=Cv
=3Ae V/d
since the area is tripled
F=kq/d
distance is more then it required less force.
so it does not depend on area
hence
The force required to keep the plates apart does not change