In a DC circuit, capacitors smooth out pulsations because they store charge in which field?

In a DC circuit, capacitors smooth out pulsations because they store charge in which field?

• A. Electric field
• B. Magnetic field
• C. Gravitational field
• D. Kinetic energy field

Answer: (A)

The key idea is that a capacitor stores energy in the electric field between its plates. When the capacitor charges, charges accumulate on opposite plates, creating a strong electric field in the dielectric between them; the stored energy is tied to that field (quantitatively, energy = 1/2 C V^2, and the field energy density is proportional to E^2). When the input voltage from a pulsating DC source drops, the capacitor releases that stored energy back into the circuit, smoothing the voltage across the load. Magnetic fields store energy in devices like inductors, not capacitors. Gravitational or kinetic energy fields aren’t the standard way we describe energy storage in typical electrical components, so they’re not the right basis for how capacitors work.

The key idea is that a capacitor stores energy in the electric field between its plates. When the capacitor charges, charges accumulate on opposite plates, creating a strong electric field in the dielectric between them; the stored energy is tied to that field (quantitatively, energy = 1/2 C V^2, and the field energy density is proportional to E^2). When the input voltage from a pulsating DC source drops, the capacitor releases that stored energy back into the circuit, smoothing the voltage across the load.

Magnetic fields store energy in devices like inductors, not capacitors. Gravitational or kinetic energy fields aren’t the standard way we describe energy storage in typical electrical components, so they’re not the right basis for how capacitors work.