(a) In Fig. 24-12a, 12 electrons (of charge -e) are equally spaced and fixed around a circle of radius R. Relative to V = 0 at infinity, what are the electric potential and electric field at the center C of the circle due to these electrons? (b) The electrons are moved along the circle until they are nonuniformly spaced over a 120° arc (Fig. 24-12b). At C, find the electric potential and describe the electric field. (a) 120

(a) In Fig. 24-12a, 12 electrons (of charge -e) are equally spaced and fixed around a circle of radius R. Relative to V = 0 at infinity, what are the electric potential and electric field at the center C of the circle due to these electrons? (b) The electrons are moved along the circle until they are nonuniformly spaced over a 120° arc (Fig. 24-12b). At C, find the electric potential and describe the electric field. (a) 120