Which quantity stores energy in an electric field caused by voltage?

• A. Inductance/Inductor
• B. Capacitance
• C. Current
• D. Reactive power

Answer: (B)

When a voltage is applied across conductors separated by a dielectric, an electric field forms between them and charges accumulate. The amount of energy that can be stored in that field for a given voltage is described by capacitance. Capacitance is the property that tells you how much charge per volt the arrangement can hold, and the energy stored in the field is E = 1/2 C V^2. So, for a given voltage, a higher capacitance means more energy stored in the electric field. Inductance stores energy in a magnetic field created by current, current is just the flow of charge, and reactive power describes energy exchange with reactive elements rather than a stored quantity.