transistor action

Question

In an n-p-n transistor, large collector current flows because:

RankGuru · Accepted Answer

In an n-p-n transistor (operating in the active region):
1. The emitter-base junction is forward biased, injecting a large number of electrons into the base.
2. The base is made **extremely thin** and **lightly doped**.
3. This ensures that only a tiny fraction (typically $< 2\%$) of these electrons recombine with holes in the base.
4. Most electrons ($> 98\%$) diffuse across the base and are 'collected' by the reverse-biased collector junction, resulting in a large collector current ($I_C \approx I_E$).

Rank Guru

transistor action

Select the correct option: