What is the current in a wire of radius R = 3.40A mm if the magnitude of the current density is given by

(a) J a = J0r and

(b) J b = J0 (1 – r/R), in which r is the radial distance and J0 = 5.50 x 10 4 A/m2?

(c) Which function maximizes the current density near the wire's surface?