A sphere of radius carries a positive charge whose volume charge density depends only…
PHYSICS · Single correct · AP · Physics C: Electricity and Magnetism · Electric Charges Fields and Gauss's Law · Electric Charges Fields and Gauss's Law
Problem
A sphere of radius R carries a positive charge whose volume charge density depends only on the distance r from the sphere's centre as ρ=ρ0(1−Rr), where ρ0 is a constant. Assume ϵ is the permittivity of space.
The magnitude of the electric field at distance r inside the sphere is given by
(1) E=ϵρ0(3r−4Rr2)
(2) E=ϵρ0(4r−3Rr2)
(3) E=ϵρ0(3r+4Rr2)
(4) E=ϵρ0(4r+3Rr2)