ABSTRACT
The two p-type material regions of the p-n-p transistor are called the emitter and collector and the n-type material is called the base. Similarly, the two n-type material regions of the n-p-n transistor are called the emitter and collector and the p-type material region is called the base, as shown in Fig. 12.1
Transistors have three connecting leads and in operation an electrical input to one pair of connections, say the emitter and base connections can control the output from another pair, say the type of
operation is achieved by appropriately biasing the two internal p-n junctions. When batteries and resistors are connected to a p-n-p transistor, as shown in Fig. 12.2(a) the base-emitter junction is forward biased and the base-collector junction is reverse biased.
