Parallel Plate Capacitor | Parallel Plate Capacitance with Dielectric

Parallel Plate Capacitor

Parallel Plate Capacitors are an arrangement of two metal plates which are electrodes and insulating material or dielectric material both plates are separated from each other by some distance there is a dielectric between them. This dielectric medium is a separator for the plates which occupies the gap between the plates as shown in fig.


Parallel plate capacitor

Parallel Plate Capacitor Diagram

The Capacitor is a passive component and it stores the electrical energy into an electrical field. The effect of the capacitor is known as a capacitance

In parallel plate capacitors used as dielectric medium such as air, vacuum, mica, porcelain, glass, paper wool, electrolytic gel and some other non conducting materials.

Working Principle of Parallel Plate Capacitor:

We know that the dielectric material does not allow the flow of electric current through it why because its non conductive property. If we can give a certain amount of charge to a plate and also supply more charge, the potential energy increases and it can be lead to leakage in the charge. In that case if we get another plate and place it next to this positively charged plate, then negative charge flows towards the side of this plate which is closer to the positively charged plate.

  •  As both the plates have charges, the negative charge on plate 2 will reduce the potential difference on plate 1.
  • On the other hand, the positive charge on plate 2 will increase the potential difference on plate 1.
  • But the negative charge on plate 2 will have more impact.
  • So, more charge can be given on plate 1. Because of the negative charges on plate 2 the potential difference will be less
  • This is the principle of the parallel plate capacitor

Parallel Plate Capacitor Formula:

Q   V

Therefore, Q = (constant)×V = CV

Where C = Capacitance of the capacitor; Q = Amount of charge stored in one capacitor; V = Potential difference between the two plates.

Where, ε = permittivity of the medium, A = overlapping plate area and d = distance separation between the plates.

Types of Capacitors:

The different types of capacitors are following.

  1. Electrolytic Capacitor
  2. Mica Capacitor
  3. Paper Capacitor
  4. Film Capacitor
  5. Non-Polarized Capacitor
  6. Ceramic Capacitor

Electrolytic Capacitor

electrolytic capacitor images

Electrolytic Capacitors are most widely used when large capacitor values required. Generally the thin metal film is used for one of the electrode and other for cathode electrode which is semi liquid electrolyte solution and which is in jelly or paste is used. Usually the dielectric plate is a thin layer of oxide, it is developed electrochemically in production with the thickness of the film and it is less than the ten microns.

Mica Capacitor

Mica-Capacitor Images

Mica Capacitors are more reliable capacitor and relatively small in size, this mica capacitors are used in small electronic pcb’s. Mica capacitors made by group of natural minerals and the silver mica capacitors used as dielectric medium. There are two types of mica capacitors which are clamped capacitors & silver mica capacitor. Clamped mica capacitors are considered obsolete due to their poor quality. Silver mica capacitors are made by sandwiching a metallic mica sheet on both sides and then the set is coated with epoxy to protect the environment.




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