Branches of electronics

Electronics has branches as follows:

1. Digital electronics
2. Analogue electronics
3. Microelectronics
4. Circuit design
5. Integrated circuits
6. Optoelectronics
7. Semiconductor devices
8. Embedded system.

Read More

What is electronics?

Electronics is a branch of physics that deals with current conduction through vacuum tube, gas and semiconductor device.

Most electronic devices use semiconductor components to perform electron control. The study of semiconductor devices and related technology is considered a branch of solid state physics, whereas the design and construction of electronic circuit to solve practical problems come under electronic engineering.

Read More

Electron Emission

The passage of electrons from a metal into a gas or vacuum is called electron emission. The mechanism of electron emission is  classified into the followings:

(1)  Thermionic emission: When energy applied to the conductor to emit electrons is in the form of heat, the process is called thermionic emission.

(2)  Photoelectric emission: When the energy applied to the metal is in the form of light energy, the process of electron emission is known as photoelectric emission.

(3)  Secondary emission: If a fast moving electron collides with the surface of the metal then the emission of electrons takes place. This is known as secondary emission.

(4)  Field emission: If the electrons are emitted from the surface of metal by maintaining a certain amount of electrostatic field between the two plats of vacuum tube then emission is known as field emission.

 Copied from GUPTA & KUMAR

Read More

Some electrical properties of semiconductors

1)Semiconductors have negative temperature coefficient of resistance i.e.. their resistivity decreases or conductivity increases rapidly with the temperature, especially at higher temperatures. Conductors, quite   contrary to the above, have positive temperature coefficient of resistance.

2)Their electrical conductivity is very much affected by even a very minute amount of impurity added to it.

Read More

Semiconductor

There are large number of materials which have resistivities lying between those of an insulator and a conductor. Such materials are known as semiconductors. At absolute zero temperature, pure and perfect crystals of the semiconductor are nonconducting, their resistivity approaching to the resistivity of an insulator.

Read More