What is the difference between a capacitor and an inductor and how are they commonly used?

Difference between Components:

Capacitor:

  • Function: A capacitor stores energy in an electric field.
  • Construction: Made of two conductive plates separated by an insulating material (dielectric).
  • Behavior:
    • In AC circuits, capacitors allow high-frequency signals to pass through while blocking low-frequency signals (acting as a high-pass filter).
    • In DC circuits, capacitors charge up to the supply voltage and then block any further current flow.

Inductor:

  • Function: An inductor stores energy in a magnetic field.
  • Construction: Made of a coil of wire, often wound around a core.
  • Behavior:
    • In AC circuits, inductors allow low-frequency signals to pass through while blocking high-frequency signals (acting as a low-pass filter).
    • In DC circuits, inductors resist changes in current flow, creating a lag in the current response.

Common Uses:

Capacitors:

  1. Filtering:
    • Power Supplies: Smooth out voltage fluctuations by filtering out noise and ripple.
    • Signal Processing: Used in filters to block or pass specific frequency ranges (e.g., high-pass or band-pass filters).
  2. Energy Storage:
    • Power Supply Circuits: Store and release energy as needed to maintain stable voltage levels.
  3. Timing Circuits:
    • Oscillators and Timers: Work with resistors to set specific time intervals in oscillators and timing circuits.

Inductors:

  1. Chokes:
    • Noise Suppression: Inductors called chokes are used to block or filter out high-frequency noise in power lines or signal paths.
  2. Filtering:
    • Power Supplies: Used in combination with capacitors to create low-pass filters that smooth out voltage fluctuations.
    • Signal Processing: Block high-frequency signals while allowing low-frequency signals to pass.
  3. Energy Storage:
    • Switching Power Supplies: Store and release energy efficiently in DC-DC converters (e.g., buck and boost converters).
  4. Transformers:
    • Power Transmission: Used in transformers to transfer energy between circuits through electromagnetic induction.