# URGENT HELP with A level Physics

A capacitor consists of two parallel plates separated by air. The capacitor is connected across
a d.c. supply. The charged capacitor is then disconnected and the separation between the
plates is doubled.
Which statement is correct about the charge stored by the capacitor?
A The charge is the same.
B The charge doubles.
C The charge halves.
D The charge quarters.

1. How is charge stored, don't capacitors store energy?
2. why is the answer A if the capacitance halves; using the equation C=EA/d
Original post by efsfsf\\eeeeeee
A capacitor consists of two parallel plates separated by air. The capacitor is connected across
a d.c. supply. The charged capacitor is then disconnected and the separation between the
plates is doubled.
Which statement is correct about the charge stored by the capacitor?
A The charge is the same.
B The charge doubles.
C The charge halves.
D The charge quarters.
1. How is charge stored, don't capacitors store energy?
2. why is the answer A if the capacitance halves; using the equation C=EA/d

The question says the supply is disconnected so there is no method by which the amount of charge on the capacitors plates can change. Where is the path for the current?

Since charge stays constant and capacitance has been reduced what do you think might have to change?
Original post by Joinedup
The question says the supply is disconnected so there is no method by which the amount of charge on the capacitors plates can change. Where is the path for the current?
Since charge stays constant and capacitance has been reduced what do you think might have to change?

I see your first point; as for the second question, if W = 1/2Q^2/C, then i guess the energy stored increases?
Original post by efsfsf\\eeeeeee
I see your first point; as for the second question, if W = 1/2Q^2/C, then i guess the energy stored increases?

Yeah, so the PD is also increased