Practicing Success

Target Exam

CUET

Subject

Physics

Chapter

Semiconductors and Electronic Devices

Question:

In common emitter amplifier the $\frac{I_c}{I_e}$ is 0.98. The current gain will be

Options:

4.9

7.8

49

78

Correct Answer:

49

Explanation:

We know that for common base $α=\frac{i_c}{i_e}=\frac{collector\, current}{emitter\, current}=0.98$

and for common emitter $β=\frac{i_c}{i_b}=\frac{collector\, current}{base\, current}$

$β=\frac{α}{1-α}=\frac{0.98}{1-0.98}=\frac{0.98}{0.92}=49$