The term 'electronics' has been coined from electron-the key particle, flow of which through a conductor gives us electric current or simply current. This current can be produced with the help of batteries and generators-machines which generate electric power either dc or ac at 50 Hz. This current can be put to use for various purpose such as illumination, heating, driving the motors. The generation, control, transmission and use of both dc and ac at 50 Hz magnitudes ranging from a few microamperes to hundreds of ampere are coming under the purview of so called electrical engineering. But electronics has far reaching capabilities and potentialities. The flow of electrons has been regulated and controlled in electronic devices under the stimuli of external influences, which may be called signal, message, data or any other name appropriate for the occasion. The controlled flow of electrons has been used through various techniques and forms what is known as electronics. In modern times, it is very difficult to find any thing starting from household goods, transports, health, communication, entertainment, multimedia, internets, where electronics has not made its presence felt.
The controlled flow of electrons has been used through various techniques and forms what is known as electronics. Besides the common electronic gadgets such as radio and TV receivers, audio and video tape recorder, frequency synthesizer, calculators, cameras, musical doorbells, etc. electronics has offered its services in different walks of life. Computer, which has revolutionized the world, is one of the major achievements of electronics.Reliability and precision are the two key factors in medical diagnostics and treatments, in laboratory practice and industrial operation. In medical diagnostics and surgery, all scanning devices and techniques use electronics in some form or the other.
An electronics circuit may appear to be complex but is capable of innumerable functions. The electronic circuit is built with a few basic components of electronics. The electronic components may be classified broadly as passive and active. Passive components are those components that cannot by themselves amplify or generate electric signals. They need to external biasing for their operation. Under this category, resistors, inductors and capacitors can be included. Resistors are dissipative elements and they offer resistance to the flow of electric current through them. They dissipate energy in the form of heat. There are many types of resistors. They may classified based on the applications, material composition, power rating and so on. Inductors and capacitors are energy storage device. They store electric energy and release as and when required. An inductor is a current controlled device whereas a capacitor is a voltage controlled device. These components can be classified based on the material used in fabrication, process of making, power rating and so on. Variable resistors, capacitors or inductors are also possible. Active devices are classified into tube devices and semiconductor devices. With the invention of compact and more efficient semiconductor devices, these tube devices find no place these days in electronics.
The network analysis or circuit analysis means to find a current through or voltage across any branch of network or circuit. Circuit
theory is based on the concept of modeling. To analyze any complex
physical system, we must be able to describe the system in terms of an
idealized model that is an interconnection of idealized elements. The
idealized elements are simple models that are used to represent or
approximate the properties of simple physical elements or physical
phenomena. In circuit theory, we study circuits made up of idealized elements and we also study their general properties. Given a physical circuit, it is possible to obtain a succession of idealized models of this circuit such that the behavior of the physical circuit. By analyzing the circuit model, we can predict the behavior of the physical circuit and design better circuits.
Electronics and electronic appliances have become the way of life in this age. With the advancement of science and technology, electronics has been introduced into industry in a large scale to meet the challenge of the modern man. Starting from the fabrication of vacuum tubes to transistors, the science of electronics has moved rapidly to fabricate integrated circuits which in turn have paved the way for generating microprocessors and super computers. Feeling the importance of electronics in the present day society, more and more people are taking interest in learning, teaching, researching and practicing electronics.