Insulating material that stores electrical energy in an electrostatic field.

Insulating material that stores electrical energy in an electrostatic field.

• A. Dielectric
• B. Correct Operation of Capacitors
• C. Electrolytic Capacitors
• D. Inductors

Answer: (A)

Storing energy in an electrostatic field relies on a dielectric, the insulating material placed between the plates of a capacitor. When a voltage is applied, the dielectric becomes polarized, which reduces the effective electric field and allows more charge to be stored for the same voltage. This increases the capacitor’s ability to store energy, described by the energy formula (1/2) C V^2, where C grows with the dielectric constant of the material. The dielectric constant, a property of the material, quantifies how well the material can polarize and thus how much energy can be stored for a given geometry and voltage. In this view, the dielectric is essential because it enables energy storage in the electric field without allowing current to flow between the plates. Other options refer to capacitor types or to energy storage in a magnetic field (as with inductors), which do not describe the insulating material that stores energy electrostatically.

Storing energy in an electrostatic field relies on a dielectric, the insulating material placed between the plates of a capacitor. When a voltage is applied, the dielectric becomes polarized, which reduces the effective electric field and allows more charge to be stored for the same voltage. This increases the capacitor’s ability to store energy, described by the energy formula (1/2) C V^2, where C grows with the dielectric constant of the material. The dielectric constant, a property of the material, quantifies how well the material can polarize and thus how much energy can be stored for a given geometry and voltage. In this view, the dielectric is essential because it enables energy storage in the electric field without allowing current to flow between the plates. Other options refer to capacitor types or to energy storage in a magnetic field (as with inductors), which do not describe the insulating material that stores energy electrostatically.