ØElectron, a negatively charged particle (charge= 1.6 X 10-19C and mass 9.1 X 10-31 kg) is a common constituent of all matter. Electrons resolve round the nucleus of an atom, in different orbits.
Ø Flow of electrons constitutes electric current.
Ø Substances which allow electric current to pass through them, are called conductors, substances which do not allow electric current to pass through them are called insulators.
ØRadio waves are electromagnetic waves. They are used for communication such as radio broadcasting, television broadcasting, satellite communication etc.
3.1 INTRODUCTION
You have seen radio, T.V., tape recorder, computer and other electronic gadgets. Have you at any time wondered.
why they are called electronic gadgets?
Or
what is meant by electronics?
The term ‘electronics’ owes its origin to the word ‘electron’. The term originally applied to the study of electron behavior and movement. Later with the advances in the knowledge about the fundamental nature of electron and about the way in which the motion of these particles could be controlled and utilized, the term came to be used in its existing broader sense.
Toady, electronics is a field of physics and engineering (both pure and applied) dealing with the design and application of devices, usually electronic devices. The operation of these depends upon the emission, behavior and effects of electrons. The development in these areas of knowledge has made it possible to manufacture a wide range of consumer, industrial and military products.
The changes that are taking place in the field of electronics, are so rapid that today’s technology may be obsolete tomorrow. Electronics finds applications in almost every walk of life. It has influenced areas such as communication, entertainment, defense, industry and medical science. The most recent advances in electronics include digital circuits, micro processors, digital computers, opto-electronics, laser technology and so on.
