# A2 AQA Physics Capacitance

#1
An electrolytic capacitor contains a very thin layer of dielectric formed when the capacitor is first charged. the insulating property of the dielectric in a certain 100mF electrolytic capacitor breaks down if the electric field strength across it exceeds 700MV/m. The maximum pd that can be applied to the capacitor is 100V.

a) Calculate the thickness of the dielectric layer
I got this correct, 0.14 micrometres

However, I don't know how to answer part b
b) The effective surface area of each capacitor plate is 1.6m^2. Estimate the energy stored per unit volume in the capacitor at 100V
Last edited by LeLivre; 1 year ago
0
1 year ago
#2
First, calculate the energy stored in the capacitor (use voltage and capacitance), then divide by the volume between plates (you know the area, and the thickness is from (a)).
0
X

new posts
Back
to top
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### Poll

Join the discussion

#### Year 12s - where are you at with making decisions about university?

I’ve chosen my course and my university (18)
31.03%
I’ve chosen my course and shortlisted some universities (22)
37.93%
I’ve chosen my course, but not any universities (2)
3.45%
I’ve chosen my university, but not my course (3)
5.17%
I’ve shortlisted some universities, but not my course (4)
6.9%
I’m starting to consider my university options (7)
12.07%
I haven’t started thinking about university yet (1)
1.72%
I’m not planning on going to university (1)
1.72%