Wood, plastic, rubber and air are good insulators because a. they conduct charge. b. charge flows easily. c. they don’t have free electrons. d. they have low resistance.

Acircular ring of charge with radius b has total charge q uniformly distributed around it. what is the magnitude of the electric field at the center of the ring? 0 keq/b2 keq2/b2 keq2/b none of these answers