Which statement is true about capacitors?

Which statement is true about capacitors?

• A. Capacitors store energy in a magnetic field
• B. Capacitors oppose a change in voltage
• C. Capacitors dissipate power as heat
• D. Capacitors require a magnetic core to operate

Answer: (B)

Capacitors store energy in the electric field between their plates and resist rapid changes in voltage. The current through a capacitor is proportional to how quickly the voltage across it changes, i = C dv/dt, so charging or discharging requires current flow that adjusts the voltage. This makes capacitors naturally oppose sudden voltage variations, which is why they’re used to smooth voltage or couple AC signals. The energy is stored electrostatically, not magnetically, so a magnetic field isn’t what a capacitor relies on. In the ideal model, a capacitor doesn’t dissipate power as heat; it transfers energy in and out rather than converting it to heat. Real capacitors can have some loss due to parasitic resistance and leakage, but the fundamental behavior remains energy storage rather than dissipation. It also doesn’t need a magnetic core—unlike inductors or transformers, capacitors are non-magnetic devices.

Capacitors store energy in the electric field between their plates and resist rapid changes in voltage. The current through a capacitor is proportional to how quickly the voltage across it changes, i = C dv/dt, so charging or discharging requires current flow that adjusts the voltage. This makes capacitors naturally oppose sudden voltage variations, which is why they’re used to smooth voltage or couple AC signals.

The energy is stored electrostatically, not magnetically, so a magnetic field isn’t what a capacitor relies on. In the ideal model, a capacitor doesn’t dissipate power as heat; it transfers energy in and out rather than converting it to heat. Real capacitors can have some loss due to parasitic resistance and leakage, but the fundamental behavior remains energy storage rather than dissipation. It also doesn’t need a magnetic core—unlike inductors or transformers, capacitors are non-magnetic devices.