A solid conducting sphere with radius R carries a positive total charge Q. The sphere is surrounded by an insulating shell with inner radius R and outer radius 2R. The insulating shell has a uniform charge density rho.

Part A

Find the value of rho so that the net charge of the entire system is zero.

Express your answer in terms of the variables Q, R, and appropriate constants. Part B

If rho has the value found in part A, find the magnitude of the electric field in the region 0
Express your answer in terms of the variables Q, R, r, and appropriate constants. Part C

If rho has the value found in part A, find the magnitude of the electric field in the region R
Express your answer in terms of the variables Q, R, r, and appropriate constants. Part D

If rho has the value found in part A, find the direction of the electric field in the region R
If rho has the value found in part A, find the magnitude of the electric field in the region r>2R.

Express your answer in terms of the variables Q, R, r, and appropriate constants. Part F

As a general rule, the electric field is discontinuous only at locations where there is a thin sheet of charge. Explain how your results in previous parts agree with this rule.