Draw the typical input and output characterisitics of an n-p-n transistor in CE configurtion . Show how these characteristic can be used to determine (a) the input resistance `(r_(1))` and (b) current amplification factor `(beta)`.

Explanation

Characteristics of Transistor in C- E configuration:
Input Characteristics: I/P ch in C - E configuration as shown. It is the curve between input current `I_(B)` base current and the I/P voltage `V_(BE)` (Bare Emitter voltage ) at constant callector emitter voltage `(V_(LE))`
Input Resistance : `r_(i) = (DeltaV_(BE))/(DeltaI_(B))|V_(CE)`= constant
Dynamic I/P resistance `r_(i)` is very small in CE configuration due to this after the cut in voltage base current `I_(B)` increase rapidly with small increase on base-emitter volt. `V_(BE)`

Output Characteristic: Output characetristic is a plate between the collector current IC and collector volt. `V_(CB)` using base current `I_(B)` as constant.
`B_(dc)` and `B_(ac)`: We know that ,
`B_(dc) = (I_(C))/(I_(B))` a.c Beta is obtained.
`B_(ac) = (DeltaI_(C))/(DeltaI_(B))`