The base current is `100 muA` and collector current is 3 mA
(a) Calculate the values of `beta,I_(e)` and `alpha`
(b) A change of `20 muA` in the base current produces a charge of 0.5 mA in the collector current. Calculate `beta_(ac)`

Explanation

`beta=(I_(C))/(I_(B))=(3xx10^(-3))/(100xx10^(-6))=30`,
`alpha=(beta)/(1+beta)=(30)/(1+30)=(30)/(1+30)=(30)/(31)=0.97`
and `I_(epsi)=(I_(C))/(alpha)=(3xx31)/(30)=3.1mA`
(b) `DeltaI_(B)=20muA=0.02mA`
`:.beta_(ac)=(DeltaI_(C))/(DeltaI_(B))=(0.5)/(0.02)=25`