Answers to those Homework Problems that you must write up and turn in at recitation (i.e. the HW problems not on the Mastering Physics web site) will be posted here. E1. proof P25. For both components, the magnitude turns out to be k(lambda)/R E2. proof W72. proof Suggested exercise from "Magnetic Field from Current Segments" Part E. -(mu_0/(4*pi))*I*dl*z_1/(x_1^2+z_1^2)^1.5 W68. (a) (pi/3)R²J_0 (b) (mu0/6r)R²J_0 (c) (mu0/2)rJ_0(1-(2r/3R))