Question

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

• A. 7
• B. 0.5
• C. 0.875
• D. 3.5

Answer 1

Answer: (A)

7

Answer 2

$I _{\varepsilon}= I _{ C }+ I _{ B }$
$\Rightarrow \Delta I _{\varepsilon}=\Delta I _{ C }+\Delta I _{ B }$
$4 mA =3.5 mA +\Delta I _{ B }$
$\Rightarrow \Delta I _{ B }=0.5 mA$
$\Rightarrow \beta=\frac{\Delta I _{ C }}{\Delta I _{ B }}$
$\beta=\frac{3.5}{0.5}$
$\Rightarrow \beta=7$