Question 119: Semiconductors and Logic Gates

Question

If an emitter current is changed by 4 mA, the collector current changes by 3.5 mA. The value of $$\beta$$ will be :

Accepted Answer

Given, emitter current, I
E
= 4 mA
Collector current, I
C
= 3.5 mA
Current gain in common base amplifier,
$$\alpha  = {{{I_C}} \over {{I_E}}}$$
$$ \Rightarrow \alpha  = {{3.5} \over 4} = {7 \over 8}$$
Also, current gain in common emitter amplifier,
$$\beta  = {\alpha  \over {1 - \alpha }}$$
$$ \Rightarrow \beta  = {{7/8} \over {1 - 7/8}}$$
$$\beta  = 7$$

Answer

0.875

Answer

0.5

Answer

3.5

Answer

7

Semiconductors and Logic Gates

If an emitter current is changed by 4 mA, the collector current changes by 3.5 mA. The value of $\beta$ will be :

Choose the correct answer: