Question

Which of the following is not the energy stored in a capacitor?

(a) \(\frac{CV^2}{2}\)

(b) \(\frac{QV}{2}\)

(c) \(\frac{Q^2}{2C}\)

(d) \(\frac{QC}{2}\)

This question was addressed to me in homework.

Asked question is from Basic Network Concepts in section Circuit Elements and Kirchhoff’s Laws of Network Theory

Answer 1

Right answer is (d) \(\frac{QC}{2}\)

The explanation is: Energy stored in a capacitor, E = \(\frac{CV^2}{2}\)

Since C = Q/V

E = \(\frac{CV^2}{2} = \frac{QV}{2} = \frac{QC}{2}\).