A) 0.2mA
B) 0.29mA
C) 0.35 mA
D) 0.4 mA
Correct Answer: B
Solution :
Key Idea: Emitter current is sum of base current and collector current. The circuit diagram is as follows. The emitter-base junction is forward biased and base-collector junction is reverse biased. Also emitter current is sum of base current and collector current, i.e., \[{{i}_{E}}={{i}_{B}}+{{i}_{C}}\] and current gain is defined as the ratio of the change in collector current to the change in emitter current at a constant collector to base voltage,\[\alpha ={{\left( \frac{\Delta {{i}_{C}}}{\Delta {{i}_{E}}} \right)}_{{{V}_{CB}}}}\] Given, \[\alpha =0.96,\,{{i}_{E}}=7.2\,mA\] \[\therefore \] \[{{i}_{C}}=\alpha \times \Delta {{i}_{E}}\] \[=0.96\times 7.2\] \[{{i}_{C}}=6.91\,mA\] Hence, base current is \[{{i}_{B}}={{i}_{E}}-{{i}_{C}}\] \[{{i}_{B}}=7.2-6.91=0.29\,mA\]You need to login to perform this action.
You will be redirected in
3 sec