Question

What is capacitance and inductance?

Answer 1

Capacitance and inductance are fundamental concepts in electrical circuits that describe how components store energy.

Capacitance:

1. Definition: Capacitance is the ability of a component (called a capacitor) to store electrical energy in the form of an electric field between two conductors.
   

1. How it works: When a voltage is applied across the plates of a capacitor, positive charge accumulates on one plate and negative charge on the other, creating an electric field. The capacitor "stores" this energy.
   

1. Measured in: Farads (F)
   

1. Formula: \( C = \frac{Q}{V} \), where:
   

  - \( C \) is the capacitance,
  - \( Q \) is the charge stored,
  - \( V \) is the voltage applied.

1. Example: A simple example is a parallel plate capacitor, where the capacitance depends on the area of the plates, the distance between them, and the material (called the dielectric) between them.
   

Inductance:

1. Definition: Inductance is the ability of a component (called an inductor) to store energy in the form of a magnetic field when current flows through it.
   

1. How it works: When an electric current flows through a coil of wire (an inductor), it creates a magnetic field around the coil. The inductor resists changes in the current, meaning it tries to keep the current constant. This property of resisting changes in current is what we call inductance.
   

1. Measured in: Henrys (H)
   

1. Formula: \( L = \frac{N \Phi}{I} \), where:
   

  - \( L \) is the inductance,
  - \( N \) is the number of turns in the coil,
  - \( \Phi \) is the magnetic flux,
  - \( I \) is the current flowing through the coil.

1. Example: A common example of inductance is a coil or solenoid, where the inductance depends on factors like the number of turns in the coil and the material inside it.
   

Key Differences:

1. Capacitance stores energy as an electric field (in a capacitor).
   

1. Inductance stores energy as a magnetic field (in an inductor).
   

1. Capacitors resist changes in voltage, while inductors resist changes in current.
   

In a simple analogy:

1. A capacitor is like a water tank storing water (energy) and releasing it when needed.
   

1. An inductor is like a heavy flywheel resisting changes in its motion (current).