IIT JEE , AIEEE Forum - Physics , Electricity

Ayush92

a point charge q = 3 $\mu$ C is located at the centre of a sphereical layer of uniform isotropic dielectric with permittivity $\epsilon$ = 3. The inside radius of the layer is equal to a = 250mm , the outside radius is b = 500mm. Find electrostatic energy inside the dielectric layer.

krishna.gopal

YOu know the field at a distance r from the charge in dielectric will be E = (9*10^9/3)*q/r^2 = (K/3)q/r^2
So energy slored per unit volume = (epsilon/2)*E^2
So total energy in dielectric is
U = (epsilon/2)*(k.3)^2*q^2/r^4*4pir^2dr integrated from a to b
= (epsilon/2)*(k.3)^2*q^2*4pi*(1/a-1/b)

gaurav_cheetah

i think we can do it by the capacitor method also.... find the capacitance of the spherical capacitor by the formula and the find the energy stored in the capacitor....
i hope i'm right....

Ask & Discuss Questions with Community & Experts