Question

The energy stored in a capacitor is equal to

A. ½ Q^2/C
B..All of these are correct
C.½ Q (ΔVC)
D. ½ C(ΔVC)^2

Answer 1

The energy stored in a capacitor is expressed in three mutually equivalent ways: ½ CV², ½ Q²/C, and ½ QV. All options provided to the student are correct.

Step-by-step explanation:

The energy stored in a capacitor is given by several equivalent expressions, which are mathematically derived from the relationship between charge (Q), voltage (V), and capacitance (C). When a capacitor is connected to a voltage source, it begins with zero potential and gradually builds up to the source voltage, with the work done to move charge being dependent on the changing voltage. Therefore, the average voltage experienced by the charge during the process is V/2. As a result, the energy (Ecap) stored in a capacitor is calculated using the following equations:

• ½ CV²
• ½ Q²/C
• ½ QV

Since all these expressions are algebraically equivalent, the correct answer to the student's question is B: All of these are correct.