TRANSISTORS

 Transistors are acting like a Electronic switch.It can be on or off depending upon the base current of 

the transistor .It has 2 types. NPN and PNP .P = positive and N = negative.a transistor basically contain

three regions doped with some impurities.it can be a NPN or PNP. when electricity passes through the base

of the transistor,It makes the semiconductor(i.e silicon) to become a conductor and thus allowing the current

to pass through the emmitter and the collector

transistor types:

NPN type

PNP type