Capacitors: find he charge for the new battery

  • Thread starter Alice7979
  • Start date
  • #1
36
2

Homework Statement


A capacitor stores 7.9 x 10-2 C of charge when connected to a 6.0-V battery. How much charge does the capacitor store when connected to a 9.0-V battery?

Homework Equations


PE=CQ/2

The Attempt at a Solution


QV^2=CQ^2
(7.9 x 10-2)(6)/2 = Q(9)
C= .05 C
 

Answers and Replies

  • #2
841
251
You are looking for an equation that relates capacitance, charge held on the plates, and the voltage across the plates.
1. Solve for capacitance.
2. Rearrange the equation and solve for charge.
 
  • #4
36
2
I guess I made that more complicated
 
  • #5
841
251
If you want to post the answer you came up with, I will see if it matches mine.
 
  • #7
841
251
That's what I got. The precision of the given data is 2 significant figures, so I rounded to 0.12 C.
 

Related Threads on Capacitors: find he charge for the new battery

Replies
8
Views
6K
  • Last Post
Replies
8
Views
2K
Replies
3
Views
21K
Replies
20
Views
8K
  • Last Post
Replies
3
Views
4K
  • Last Post
Replies
18
Views
2K
  • Last Post
Replies
3
Views
65K
Replies
0
Views
2K
Replies
2
Views
631
Top