AIIMS AIIMS Solved Paper-2001

  • question_answer
    The current gain for a transistor works if common-base amplifier is 0.96. If the emitter current is 7.2 mA, the base current will be;

    A)  0.42mA                               

    B)  0.49mA                               

    C)  0.29 mA              

    D)         0.35 mA

    Correct Answer: C

    Solution :

                    Key Idea: Current gain in common-base amplifier is ratio of change in collector current to change in emitter current. Current gain of transistor is \[_{Z}{{X}^{A}}{{\xrightarrow{{}}}_{Z-2}}{{Y}^{A-4}}{{+}_{2}}H{{e}^{4}}\] where, \[\alpha \] is change in collector current, and \[~{{\lambda }_{m}}T=constant\] is change in emitter current. Given, \[\lambda \] \[\therefore \] Also    \[\int{E.dA=\frac{q}{{{\varepsilon }_{0}}}}\] \[=\frac{1}{6}\times \frac{q}{{{\varepsilon }_{0}}}=\frac{q}{6{{\varepsilon }_{0}}}\]   \[E=\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{(-2Q)}{r}\] \[E=\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{(Q)}{r}\]


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