Question

Which of the following statements are true?
Check all that apply.

A) The electric field between the plates of a parallel-plate capacitor is uniform.
B) A capacitor is a device that stores electric potential energy and electric charge.
C) The capacitance of a capacitor depends upon its structure.
D) A capacitor consists of a single sheet of a conducting material placed in contact with an insulating material.

Answer 1

I think it's just A and B

Answer 2

i think A , B , C

Answer 3

for an answer I had a and c, idk is b would count

Answer 4

The structure of a capacitor can be cylindrical, it could be a parallel plate capacitor, etc. Shape and structure are irrelevant

Answer 5

because the area of the insulator sheets decides the amount of charge that can be stored in the capacitor... area is a part of structure.. so it counts

Answer 6

I am confused, they both sound like great answers, but if structure counts, that is where the volume of the shapes come into play with math problems, volume is different for a circle and a cylinder so that means shapes do count,,,right?

Answer 7

Ok I guess it's a matter of wording
Let me explain what I mean

Answer 8

The capacitance is defined by
\[C={Q\over\Delta V}\]
Q is the charge and delta V is the voltage difference.
Sometimes a dielectric material will be placed inside a capacitor to increase it's capacitance since it decreases the voltage difference. The smaller the voltage difference, the greater the capacitance. The wording of choice C states

C) The capacitance of a capacitor depends upon its structure.

Insulating material is independent of the structure of the capacitor since it can be removed. So I suppose the third choice depends on whether or not you consider insulating material to be part of the structure.

Answer 9

that is a good point as well, ahh I hate how the teacher makes it so vague.

Answer 10

ok.. then let me ask u this...
if the structure doesn't affect
why r there separate formulas to the capacitance of cylindrical capacitor and parallel plate capacitor and so on ...
http://web.mit.edu/viz/EM/visualizations/coursenotes/modules/guide05.pdf

Answer 11

ok, for a cylindrical capacitor, if you are just a VERY VERY small charge there, do you agree that all you see is an infinitely flat surface?

Answer 12

a cylindrical capacitor's equation can be reduced to that of a parallel plate capacitor. If they were truly that different, you couldn't find such a correlation.

Answer 13

but... if there is no effect.. then there is no need to write 2 equations and above all there will be no need to produce 2 structures...

Answer 14

Parallel plate capacitor
\[\huge C=\epsilon_0{A\over d}\]

Cylindrical capacitor
\[\huge {2 \pi l \epsilon_0}\over {\ln {b\over a}}\]

Ok, @***[ISURU]*** you make a very valid point
I will concede

Answer 15

***[ISURU]*** you are correct, you guys are awesome, thank you so much for your help!