(a) {2 points) A line of charge with uniform charge density A extends from z = a to z = a + d. {So d is the length of the charge.) Find the dipole moment of this charge distribution. Does it depend on where you place it, that is, on the value of a? What is the total charge of the line? (b) {2 points) Another line has nonuniform charge density M2), where the charge density A 1varies linearly from ).0 at z = a to +An at z 2 (1+ d. Same questions: what is the dipole moment, does it depend on a, what is the total charge? (2 points) Point charges +q are placed at z : +d/2 and z = d/2 on the z axis. Another charge, 2q, is at the origin. Find the leading-order term in the potential expansion V0", 9) = Z BgT_i_1H(COS 6) (1) for r 33> d. (This is one realization of a quadrupole term.)