Capacitor-Types of Capacitor and Capacitance: What is a Capacitor? (For CBSE, ICSE, IAS, NET, NRA 2022)

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Title: Capacitor - Types of Capacitor and Capacitance

What is a Capacitor?

  • The capacitor is a device in which electrical energy can be stored.
  • It is an arrangement of two-conductor generally carrying charges of equal magnitudes and opposite sign and separated by an insulating medium.
  • It is a passive electronic component with two terminals.
  • The effect of a capacitor is known as capacitance.
  • Capacitor vary in shape and size, they have many important applications in electronics.

Use of Capacitors

Capacitors have many uses in electronic and electrical systems:

  • Storing electric potential energy
  • Filtering out unwanted frequency signals
  • Delaying voltage changes when coupled with resistors.
  • One of the conductors has a positive charge + Q and it is at potential + V. whereas the other has an equal negative charge, -Q and is at potential – V.

They are so ubiquitous that it is rare that an electrical product does not include at least one for some purpose.

Charge on Capacitor

Total charge/the net charge on the capacitor is .

Image of Capacitor

Capacitor Image


  • The charge on the capacitor (Q) is directly proportional to the potential difference (V) between the plates

  • The constant of proportionality (C) is termed as the capacitance of the capacitor.
  • Unit of Capacitance: Farad (F)
  • Dimensional Formula:

Factors Affecting the Capacitance

  • Shape and size of the conductor
  • Medium between them
  • Presence of other conductors near it.

Types of Capacitor

Parallel Plate Capacitor

Parallel Plate Capacitor
  • The parallel plate capacitor is the simplest form of capacitor.
  • It can be constructed using two metal or metallized foil plates at a distance parallel to each other, with its capacitance value in Farads, being fixed by the surface area of the conductive plates and the distance of separation between them.

Spherical Capacitor

Spherical Capacitor
  • A spherical capacitor consists of a hollow or a solid spherical conductor surrounded by another concentric hollow spherical conductor.
  • The capacitance of a spherical capacitor is derived as: By Gauss law charge enclosed by gaussian sphere of radius r be.

Cylindrical Capacitor

Cylindrical Capacitor
  • The capacitor is used to store large amounts of electric current in a small space.
  • It is often used to store the electric charge.
  • The Cylindrical capacitor is a type of capacitor that possess the shape of a cylinder having an inner radius as a and outer radius as b.

Developed by: