Calculate the energy stored in 20μF capacitor if the potential difference between the plates is 40V.

A. 3.2 x10−²J
B. 1.6×10²J
C. 8.0×10^-4J
D. 4.0×10^-4J
E. 2.0×10^-4J

Correct Answer:

Option B – 1.6×10²J

Explanation

E = ½cv² = 1/2 x 10 x 10-6 x 40² = 1.6 x 10²J