Question
For an n-p-n transistor in the common emitter configuration, draw a labelled circuit diagram of an arrangement for measuring the collector current as a function of collector emitter voltage for at least two different values of base current. Draw the shape of the curves obtained. Define the terms:
(i) ‘output resistance’ and (ii) ‘current amplification factor’ .
Solution
Circuit diagram for drawing characteristics of a common emitter n-p-n transistor is given as follows:
The output characteristics are drawn by plotting current IC versus collector emitter voltages VCE, keeping the base current Ib constant.
Output resistance:
It is defined as the ratio of the collector emitter voltage (ΔVCE) to the corresponding change in collector current (ΔIC) at a constant base current lb.
Current amplification factor:
It is defined as the ratio of the change in collector current to the change in base current.
The output characteristics are drawn by plotting current IC versus collector emitter voltages VCE, keeping the base current Ib constant.
Output resistance:
It is defined as the ratio of the collector emitter voltage (ΔVCE) to the corresponding change in collector current (ΔIC) at a constant base current lb.
Current amplification factor:
It is defined as the ratio of the change in collector current to the change in base current.
