Hardware & Software System

Electronics The branch of engineering which deals with current conduction through a vacuum or gas or semiconductor is known as Electronics.                    Electronics essentially deals with electronic devices and their utilisation. An electronic device is that in which current flows through a vacuum or gas or semiconductor. Such devices have valuable properties which enable them to function and behave as the friend of man today. 

Ferromagnetic  materials have a large, positive susceptibility to an external magnetic field. When a magnetizing force is applied, the domains become aligned to produce a strong magnetic field within the part. Iron, nickel, and cobalt are  examples  of  ferromagnetic  materials.

Ferrimagnetism , type of permanent magnetism  that occurs in solids in which the magnetic fields associated with individual atoms spontaneously align themselves, some parallel, or in the same direction (as in ferromagnetism), and others generally antiparallel, or paired off in opposite directions. The magnetic behaviour of single crystals of ferrimagnetic materials may be attributed to the parallel alignment; the diluting effect of those atoms in the antiparallel arrangement keeps the magnetic strength of these materials generally less than that of purely ferromagnetic solids such as metallic iron .

A transistor amplifier must satisfy three basic conditions, namely :   1) proper zero signal collector current.   2) proper base-emitter voltage at any instant and   3) proper collector-emitter voltage at any instant. It is the fulfilment of these conditions which is known as transistor biasing.          The proper flow of zero signal collector current and the maintenance of proper collector-emitter voltage during the passage of signal is known as transistor biasing.

The basic function of transistor is to do amplification.The weak signal is given to the base transistor and amplified output is obtained in the collector circuit. One important requirement during amplification is that only the magnitude of the signal should increase and there should be no change in signal shape. this increase is magnitude of the signal without any change in shape is known as faithful amplification . In order to achieve this,means are provided to ensure that input circuit of the transistor remains forward biased and output circuit always remains reverse biased during all parts of the signal. This is known as transistor biasing.

A pn junction is known as a semi-conductor or * crystal diode .                The outstanding property of a crystal diode to conduct current in one direction only permits it to be used as rectifier. A crystal diode is usually represented by the schematic symbol shown in fig 1. The arrow in the symbol indicates the direction of easier conventional current flow. fig. 1      A crystal diode has two terminals. When it bis     connected in a circuit one thing to decide is         whether the diode is forward or reverse biased.     There is an easy rule to ascertain it. If thew external circuit is trying to push the conventional current in the direction of arrow, the diode is forward biased. On the other hand, if the conventional current is trying to flow opposite to arrowhead, the diode is reverse biased. Putting on the simple words :         1) If a...