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There are two types of transistoy i.e, Page 1 of 17, page-.he Per )ca, Bipolay Junction Transistor CBJT), *BJT ( Bipolay Junetion Fransistor )-, An 'electronic device that consists of two, P-n., Junetion, formed by sandwitching either, P-type or n- type semičonductor between a, pair of opposite layey is known as transis tor, Three' doped région arre emitter, base and, collector., Emitter (E):- It is heavily doped semiconductoy, and it's size is largey tRan Base less than, collector. It's funcEion is to emit electrons, or holes into the base., 2) Base CB): - It is lightly doped semieonductor. IE'S, wid th is smallest of the three region. It's, function is to pass most. of the electron or holes, to the collector., 3) Collector cc):- The doping level of the collector, is intermediate between the emitter and base., It's, of hotes Pa region.It's function is to cotlect, the, size is the Targest of the three eteetrons, electrons or, holes Prom the base., Types of transistor:-, There, Dn-p-n transistor., 12) P-n-P tan'sis tor., are two types of transistoy i.e, n-p-n transistor:, The two n-region and, called, are show n id fiqure, one, -n transistor, The, p-region is, transistor

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Page 2 of 17, Base region, Emitter, Collector, Symbel, pn transistor, transistor, B., IB, VCC, VEE, tig-structure of, Emitter bas e junction is forword biased, the collector base junc ti on is neversed biased., It is called F-R bias, Because of E-B junction is forward s ed, and VBE>0.7 volt large number of electron, enter the emitter. This qives rise to emit, curment IE ., - As the base is very thin and lightly doped,, it has feuw holes.Few electrons From' the, emitter recombine with these holes and come, out as base current IB ., |-most of the emitter injected electrons, find reverse biased c-B junction and enter, the collector, then more into positive, terminal oF Sourre Vec that produces large., Collector current Ic., |- more than 95%. Emitterr Pnjected electron, enter into collector and less than 5/., recombine with the hole in base. Therefore, IB is very small compored to Ic., n-p-n transistor., as shown in fiq, ...'