A parallel-plate capacitor has plates with an area of 451 cm2 and an air-filled
ID: 1683350 • Letter: A
Question
A parallel-plate capacitor has plates with an area of 451 cm2 and an air-filled gap between the plates that is 2.51 mm thick. The capacitor is charged by a battery to 575 V and then is disconnected from the battery.(a) How much energy is stored in the capacitor?
____________J
(b) The separation between the plates is now increased to 10.04 mm. How much energy is stored in the capacitor now?
____________J
(c) How much work is required to increase the separation of the plates from 2.51 mm to 10.04 mm?
_____________ J
Explain your reasoning.
Explanation / Answer
The way you actually figure out the answer to (b) is the following:
x/y. Where x = the new distance the two plates are separated and y=the distance the plates were separated initially. Use this ratio (x/y) and multiply by the answer you got from part (a)
Hope this helps.