Q114 / 150 · MHT CET 2026 (13 April Shift 1) · Physics
In transistor amplifier, base emitter junction is forward biased and collector base junction is reversed biased. The current gain is
- Correct answerA$\dfrac{\Delta I_C}{\Delta I_B}$
- B$\dfrac{\Delta I_B}{\Delta I_C}$
- C$\dfrac{\Delta I_E}{\Delta I_B}$
- D$\dfrac{\Delta I_B}{\Delta I_E}$
Solution
In a standard transistor amplifier (common-emitter configuration), the input signal is applied to the base terminal and the output is taken from the collector terminal.
The AC current gain ($\beta$) is defined as the ratio of the change in output current (collector current, $\Delta I_C$) to the change in input current (base current, $\Delta I_B$) at a constant collector-emitter voltage.
$\beta = \dfrac{\Delta I_C}{\Delta I_B}$
The AC current gain ($\beta$) is defined as the ratio of the change in output current (collector current, $\Delta I_C$) to the change in input current (base current, $\Delta I_B$) at a constant collector-emitter voltage.
$\beta = \dfrac{\Delta I_C}{\Delta I_B}$
Hence, the correct answer is option: 'A'.