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

Explanation

The collector current `(I_(C))` of a transistor is a function of base current `(I_(B))` and the collector -emitter voltage `(V_(CE))` . The output resistance of a transistor is
`r_(0)=(DeltaV_(CE))/(DeltaI_(C))` when `(I_(B))` is kept constant.
On the linear graph in the active region of the output characteristics two convenient points are chosen on line representing a fixed `I_(B)`. The coordinates of the points `(V_(CE)I_(C)) "and" (V'_(CE)I'_(C))` are recorded . Then `r_(0)` is calculated from the relation
`r_(0)=(V_(CE)-V_(CE))/(I_(C)-I_(C))`