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

a. 7

b. 0.875

c. 0.5

d. 3.5

Given:

ΔIE = 4 mA

ΔIC = 3.5 mA

We know that, α = ΔIC / ΔIE

⇒ α = 3.5 / 4 = ⅞

Also, β = α / 1-α, so

$\beta = \frac{\frac{7}{8}}{1-\frac{7}{8}} = \frac{7}{1}$

β = 7