Aplastic rod has been bent into a circle of radius r = 8.00 cm. it has a charge q1 = +2.70 pc uniformly distributed along one-quarter of its circumference and a charge q2 = −6q1 uniformly distributed along the rest of the circumference. take v = 0 at infinity. (a) what is the electric potential at the center c of the circle? v (b) what is the electric potential at point p, which is on the central axis of the circle at distance d = 6.71 cm from the center?