A solid, isolated conducting sphere of radius carries an unknown positive net charge.…
PHYSICS · Multi-part · AP · Physics C: Electricity and Magnetism · Electric Charges Fields and Gauss's Law · Electric Charges Fields and Gauss's Law
Problem
A solid, isolated conducting sphere of radius R carries an unknown positive net charge. A group of students discusses how the magnitude of the electric field E produced by the sphere varies with the radial distance r measured outward from the center of the sphere.
(a) Describe qualitatively how the magnitude of E depends on r for the regions 0≤r<R and r>R.
(b) Without drawing an actual picture, clearly describe the main features that a graph of E versus r would display for all values of r≥0. Your description should mention any discontinuities, extrema, or asymptotic behavior.
(c) Suppose instead that the sphere were a solid, uniformly charged insulating sphere with the same total charge and the same radius R. Explain how and why the graph you described in part (b) would be different for the region 0≤r<R.