Energy of a parallel plate capacitor homework

samedi 30 novembre 2013

Hi all



"A parallel plate capacitor in which plates of area A are separated by a distance d, has a capacitance C = [itex]\frac{Aε_{0}ε_{r}}{d}[/itex]

It is charged to a pd V. Neglecting edge effects, derive an equation for the electric field E in the capacitor, and show that the energy stored per unit volume is w= 0.5[itex]ε_{r}ε_{0}E^{2}[/itex]"



I believe that the electric field in a capacitor to be equal to [itex]\frac{\sigma}{\epsilon_{0}}[/itex]

via Gauss Law, and using V = Ed you can then get V = [itex]\frac{\sigma d}{\epsilon_{0}}[/itex].



I have then tried to use the various equations for work done = 0.5CV^2, 0.5QV etc to no avail.



Any help much appreciated.



Thanks






via Physics Forums RSS Feed http://www.physicsforums.com/showthread.php?t=725799&goto=newpost

0 commentaires:

Enregistrer un commentaire