- #1
- 123
- 5
Homework Statement
Let ρ(r)= Qr/πR4 be the charge density distribution for a solid sphere of radius R and total charge Q.For a point 'P' inside the sphere at distance r1 from the centre of the sphere, the magnitude of electric field is ?
A) 0
B) Q/4πε°(r1)2
C) Q(r1)2/4πε°R4
D) Q(r1)2/3πε°R4
Homework Equations
The Attempt at a Solution
Constructing a spherical gaussien surface on which point P lies,
Φ= EΔs=q/ε°
E4π(r1)2= q/ε°
where q is the charge enclosed by the gaussien surface.
I'm having trouble as I don't know how to find q. I know dq= ρdv and so q=∫ ρdV , but if I do substitute ρ in that integral , I don't know what to do with the dV.
Please give me a hint as to how to proceed.