(a) Describe briefly the functions of the three segments of n-p-n transistor.
(b) Draw the circuit arrangement for studying the output characteristics of n-p-n transistor in CE configuration. Explain how the output characteristics is obtained.
(a) The three segments of n-p-n transistor are:-
(i) Emitter: It is of moderate size and heavily doped. It supplies a large number of majority carriers for the current flow through the transistor.
(ii) Base: This is the central segment. It is very thin and lightly doped. Allows most of the majority carriers to pass to the collector
(iii) Collector: This segment collects a major portion of the majority carriers supplied by the emitter.
It is larger in size than emitter.
(b) When a transistor is used in CE configuration, the input is between the emitter and the base and the output is between the collector and the emitter.
The variation of the collector current with the collector - emitter voltage
keeping the base current
constant is called the output characteristic.
The output characteristic is obtained by keeping constant and by observing the variation of
as
.