Question

The typical output characteristics curve for a transistor working in the common-emitter configuration is shown in the figure. The estimated current gain from the figure is ________. 

Hint:

In the active region, the output curves are nearly horizontal, meaning \(\beta\) is fairly constant.

Answer 1

Correct Answer: 200

Step 1: Current gain (\(\beta\)) in common-emitter configuration is the ratio of change in collector current (\(\Delta I_C\)) to change in base current (\(\Delta I_B\)) at a constant collector-emitter voltage (\(V_{CE}\)).
Step 2: From the typical graph: If \(I_B\) changes from \(10 \mu A\) to \(20 \mu A\) (\(\Delta I_B = 10 \mu A\)), and \(I_C\) changes from \(2 mA\) to \(4 mA\) (\(\Delta I_C = 2 mA\)).
Step 3: Calculate \(\beta\). \[ \beta = \frac{\Delta I_C}{\Delta I_B} = \frac{2 \times 10^{-3}}{10 \times 10^{-6}} = 200 \]