Question

In a silicon transistor, a change of `8.0 mA` in the emitter current produces a change of `7.9 mA` in the collector current. What change in the base current is necessary to produce an equivalent change in collector current?

Answer 1

Here, `DeltaI_(E)=8.0mA, DeltaI_C=7.9mA`
As `alpha_(a.c.)=(DeltaI_C)/(DeltaI_(E))=(7.9mA)/(8.0mA)=0.9875`
Now `beta_(a.c.)=alpha/(1-alpha)=0.9875/(1-0.9875)=79`
`:.DeltaI_(B)=(DeltaI_(C))/(beta_(a.c.))=(7.9mA)/79=0.1mA`