Physics / Calculating energy on a capacitor
Favorites|Homepage
Subscriptions | sitemap
HOME > Physics > Physics / Calculating energy on a capacitor

Physics / Calculating energy on a capacitor

[From: ] [author: ] [Date: 11-04-30] [Hit: ]
same answer.I dont see where you got a factor of 16 ??.......
If the potential difference across a capacitor is doubled, by what factor does the energy stored change?

Knowing that U=1/2QV and U=1/2CV^2 i can use one formula and get that the energy increases by a factor of 4, while i use the other formula and get the energy increasing by a factor of 16.

How do i know which formula to use?

-
goes up by a factor of 4, using U = ½CV², since C is unchanged.

yes, there are other formulae:
U = ½CV² = ½QV = ½Q²/C Energy in a cap in Joules
You have to use Q = CV, which means when you double the voltage, Q also doubles

you used U = ½QV. Q doubles because V doubles, so the total is two doublings, or 4x, same answer.

You then used U = ½CV², V doubles, 2 squared is 4, same answer.

I don't see where you got a factor of 16 ??

.
1
keywords: capacitor,energy,on,Calculating,Physics,Physics / Calculating energy on a capacitor
New
Hot
© 2008-2010 http://www.science-mathematics.com . Program by zplan cms. Theme by wukong .