Question

Draw a typical output characteristics of an n-p-n transistor in CE configuration. Show how these characteristics can be used to determined output resistance .

Answer 1

Output characteristics is the plot between collector-emitter voltage $\left(V_{CE}\right)$ and the collector current $\left(I_C\right)$ at different constant values of base current $\left(I_B\right)$.(IB)
Output resistance is defined as the ratio of the change in collector- emitter voltage $\left(\Delta V_{CE}\right)$(ΔVCE) to the change in collector current $\left(\Delta I_C\right)$at a constant base current $I_B$
Initially with the increase in$V_{CE}$VCE the collector current increase almost linearly this is because the junction is not reverse biased. When the supply is more than required to reverse bias the base -collector junction $I_C$IC increase very little with $V_{CE}$
The reciprocal of slope of the linear part of the curve gives the value of output resistance.