Question

A hollow non-conducting spherical shell has inner radius R1=5 cm and outer radius R2=12 cm. A charge Q=-25 nC lies at the center of the shell. The shell carries a spherically symmetric charge density Q=Ar for R1 < r < R2 that increases linearly with radius, where A 21 uC/m⁴ 

Part (a) Write an equation for the radial electric field in the region r < R1 in terms of Q, r, and Coulomb's constant k. You may take the positive direction as outward.

Part (b) What is the radial electric field at the point r = 0.5R1? Given your answer in units of kN/C, and take the positive direction outwards. 

Part (c) What is the radial electric field at the point r 0.5(Rl+R2)? Give your answer in units of kN/C 

Part (d) What is the radial electric field at the point r = 2R2? Give your answer in units of kN/C.

Answer 1

Here we have to find the charge enclosed and then that charge can be treated as positioned at center for calculation of electric field.