Where does a capacitor store its energy?

A capacitor stores its energy in the electric field that is created between its plates when a voltage is applied across them. This occurs because a capacitor consists of two conductive plates separated by an insulating material known as a dielectric. When a voltage is applied, positive and negative charges accumulate on the plates, establishing an electric field. This electric field is where the energy is stored; the amount of energy stored in a capacitor is proportional to the voltage across the plates and the capacitance value, which reflects the capacitor's ability to hold charge.

The other options do not accurately reflect the mechanism of energy storage in a capacitor. The copper leads are merely conductors for connecting the capacitor to a circuit and do not store energy themselves. The energy is not stored in a magnetic field for a capacitor, as it would be in an inductor where energy is stored in the magnetic field produced by the current flowing through a coil. Lastly, while a resistor may dissipate energy in the form of heat, it does not contribute to the energy storage capability of a capacitor.