Along metal cylinder with radius a is supported on an insulating stand on the axis of a long, hollow, metal tube with radius b. the positive charge per unit length on the inner cylinder is l, and there is an equal negative charge per unit length on the outer cylinder. (a) calculate the potential v1r2 for (i) r 6 a; (ii) a 6 r 6 b; (iii) r 7 b. (hint: the net potential is the sum of the potentials due to the individual conductors.) take v = 0 at r = b.