question_answer

Graph of input characteristic of common emitter amplifier is

A)  

B)   

C)  

D)   

Correct Answer: B

Solution :

 The input characteristics of common emitter amplifier is the curve between base current \[{{I}_{B}}\] and base-emitter voltage \[{{V}_{BE}}\] at constant collector-emitter voltage \[{{V}_{CE}}\]. The input characteristics can be determined by the circuit shown in figure. Keeping \[{{V}_{CE}}\]constant (say at 0 V), note the base current \[{{I}_{B}}\] for various values of \[{{V}_{BE}}\]. Then, plot the readings obtained on the graph, taking \[{{I}_{B}}\] along V-axis and \[{{V}_{BE}}\] along X-axis. This gives the input characteristic at\[{{V}_{CE}}=0\,V\]. Following a similar procedure, a family of input characteristics can be drawn. These curves are similar to as shown in option