Electrical Engineering XYZ MCQs
The majority carriers in the emitter of a PNP transistor are:
- Trivalent atoms
- Holes
- Pentavalent atoms
- Free electrons
Correct answer: 2. Holes
Explanation: The majority carriers in the emitter of a PNP transistor are holes.
In a PNP transistor, there are three regions: emitter, base, and collector. The emitter is P-doped, which means it has an excess of positively charged “holes” due to the presence of trivalent (three valence electrons) atoms.
When a small forward bias voltage is applied to the base-emitter junction, it allows the majority carriers (holes in the P region) to diffuse into the base region, which is very thin. In this process, minority carriers (electrons in the P region) are injected into the base. However, because the base region is thin, most of these minority carriers reach the collector-base junction without recombining with majority carriers.
So, in summary, the majority carriers in the emitter of a PNP transistor are holes, which are positively charged carriers generated due to the presence of trivalent atoms in the P-doped region.