If the potential difference of a capacitor is reduced by one-half,the energy stored in that capacitor is
A)reduced to one-half.
B)reduced to one-quarter.
C)increased by a factor of 2.
D)increased by a factor of 4.
E)not changed.

Question

Quizplus · Accepted Answer

The energy stored in a capacitor is given by the formula E = (1/2)CV^2, where C is the capacitance and V is the potential difference. If V is reduced by one-half, then the energy stored in the capacitor becomes E = (1/2)C(V/2)^2 = (1/2)CV^2/4 = (1/4)CV^2. Therefore, the energy stored in the capacitor is reduced to one-quarter of its initial value.

If the Potential Difference of a Capacitor Is Reduced by One-Half,the