An electric insulator is a material: A. Containing no electrons B. Through which electrons do not flow easily C. That has more electrons than protons on its surface D. Cannot be a pure chemical element

B.

Explanation:

The ability of a substance to conduct electricity depends on the free electrons it has.

An electric insulator is a material in which electrons have little freedom to move. For this reason, they are bad conductors of electricity and are used in producing insulating materials. They however contain electron.

Conductors on the other hand are materials whose electrons are very free to move. Hence they are very good conductors of electricity

v=ir = 3x15 =45 v

energy stored in the capacitor= 9.72 x 10⁻⁴ j

explanation:

the energy stored in the capacitor is given by

e= 1/2 c v²

e= energy stored

c= capacitance= 1.5 µc= 1.5 x 10⁻⁶f

v= potential difference=36 v

so energy stored= e= 1/2 (1.5 x 10⁻⁶) (36)²

energy stored= 9.72 x 10⁻⁴j