Question

A +22.5 nC point charge is surrounded by a concentric conducting spherical shell of radius 2.40 cm that carries a charge of ?31.0 nC. Derive expressions for the electric field as a function of radial distance both inside and outside the shell? E(r < 2.40 cm) = N/C, direction ---Select--- radially inward radially outward

E(r > 2.40 cm) =   N/C, direction ---Select--- radially inward radially outward

Answer 1

The point charge (in this case it is positive) will attract all negative charge toward the inner (randomly shaped) surface of the sphere, while repelling positive charge to the outside surface of the sphere. This is clear.

However, are the outer (positive) charges uniformly distributed across the sphere regardless of where the cavity's shape and position of the point charge, hence allowing the calculation of electric field outside the sphere to be considered equal to a point charge located at the center of the sphere. Or does the charge location and inner shape of the sphere affect the field outside the sphere? if yes, how? can we still calculate the charge simply by considering the actual position of the point charge to be the distance with which we calculate

E=(k(q1)(q2))/(r^2)