25. Electric Potential
Equipotential Surfaces
25. Electric Potential Equipotential Surfaces
2PRACTICE PROBLEM
A hollowed brass sphere has a radius rb and carries a change +q. A solid aluminum ball of radius ra carrying a charge -q is located at the center of the hollowed brass sphere. Insulating materials are used to hold the ball in place. Use E(r) = -∂V/∂r = (-∂/∂r)(kq/r) = kq/r2 and the expression for electric potential outside the brass sphere to obtain an expression for the electric field outside the brass sphere.
A hollowed brass sphere has a radius rb and carries a change +q. A solid aluminum ball of radius ra carrying a charge -q is located at the center of the hollowed brass sphere. Insulating materials are used to hold the ball in place. Use E(r) = -∂V/∂r = (-∂/∂r)(kq/r) = kq/r2 and the expression for electric potential outside the brass sphere to obtain an expression for the electric field outside the brass sphere.