please solve part b and c

Find an expression for the electric field strength inside the metal as a function of the radius r from the center. Express your answer in terms of the variables I, o, 7, and appropriate constants. A hollow metal sphere has inner radius a, outer radius b, and conductivity o. The current I is radially I outward from the inner surface to the outer surface. E= (4172) Submit Previous Answers Correct Part B Evaluate the electric field strength at the inner surface of a copper sphere if a = 1.2 cm , b = 2.5 cm , and / = 20 A Express your answer to two significant figures and include the appropriate units. E= Value Units Submit Request Answer Part C Evaluate the electric field strength at the outer surface of a copper sphere if a = 1.2 cm , b =2.5 cm , and I = 20 A Express your answer to two significant figures and include the appropriate units. E = Value Units