Question
(i) Write the functions of three segments of a transistor.
(ii) Draw a circuit diagram for studying the input and output characteristics of a n-p-n transistor in common emitter configuration. Using the circuit, explain how input, output characteristics are obtained.
Solution
i) The function of three segments of a transistor are:
Emitter: Emits the majority charge carriers
Collector: Collects the majority charge carriers
Base: Base provides the interaction between the collector and the base
ii) An n-p-n transistor is as shown below:
Input characteristics: The variation between the base current and the base-emitter voltage is obtained. Input characteristics is used to find input dynamic resistance of the transistor as it is represented by the slope.
Output characteristics: A graph representing the variation of the collector current and emitter voltage is obtained, keeping base current fixed. The slope fo the output characteristic graph gives us the output dynamic resistance.
