JEE Main & Advanced Physics Semiconducting Devices Question Bank Junction Transistor

  • question_answer
    In a PNP transistor working as a common-base amplifier, current gain is 0.96 and emitter current is 7.2 mA. The base current is        [AFMC 2002; Pb. PET 2002]

    A)            0.4 mA                                    

    B)            0.2 mA

    C)            0.29 mA                                  

    D)            0.35 mA

    Correct Answer: C

    Solution :

                       \[\alpha =\frac{{{i}_{c}}}{{{i}_{e}}}\]=0.96 and ie = 7.2 mA                    \[\Rightarrow {{i}_{c}}=0.96\times {{i}_{e}}\]= 0.96 ´ 7.2 = 6.91 mA                    \[\therefore {{i}_{e}}={{i}_{c}}+{{i}_{b}}\]Þ 7.2 = 6.91 +  ib Þ ib = 0.29 mA.


You need to login to perform this action.
You will be redirected in 3 sec spinner