Question

Write the relation between alpha and beta in transistor

Answer 1

Answer:

Explanation:

The terms Alpha and Beta refer to BJTs, Bipolar Junction Transistors. In these devices current leaves the emitter and crosses to the base and most is diverted towards the collector. The remainder leaves the base terminal.

Using a convenient notation, Ie = Ic + Ib

So Ib = Ie - Ic

Alpha is the proportion of Ie that flows to the collector,

ɑ = Ic/Ie ————— Definition

So Ic = ɑ Ie

Also Ib = Ie - ɑ Ie = Ie(1 - ɑ)

Beta is the current gain, the ratio of Ic to Ib.

β = Ic/Ib ————— Definition

Substituting in this definition for Ib and Ic

β = (ɑ Ie)/ Ie(1 - ɑ)

Cancelling Ie leaves:

β = ɑ/(1 - ɑ) ——————Q.E.F.