Calculate the energy stored in a 20μF capacitor. If the p.d between the plates is 40V.

A. 3.2 x 10‾²J
B. 1.6 x 10‾²J
C. 8.0 x 10^-4J
D. 4.0 x 10^-4J

Correct Answer: Option B

Explanation

W = cv²/2=(20×10^−6×40²)/2

= 1.6 x 10‾²J