When a PN junction diode is forward biased, the flow of current across the junction is mainly due to:
Correct answer: B. Diffusion of charges
- A. Drift of charges
- B. Diffusion of charges
- C. Both drift and diffusion of charges
- D. Depends on the nature of the material
Explanation
In a forward-biased P-N junction diode, the applied voltage reduces the barrier potential, allowing majority carriers to move across the junction. Electrons from the N-type region move into the P-type region, and holes from the P-type region move into the N-type region. This movement of majority carriers is due to diffusion, as they move from a region of high concentration to low concentration. As a result, the current flow in a forward-biased diode is primarily due to diffusion. Other options are incorrect because:Drift of charges: Drift is driven by an electric field, which is not the main process in forward bias.Both drift and diffusion of charges: Although both phenomena can occur, diffusion is the dominant process in this context.Depends on the nature of the material: The basic operation of a P-N junction is independent of the material type regarding majority carrier movement.
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About Electronics
A p-n junction forms when p-type and n-type semiconductor regions meet, creating a depletion layer, barrier potential and rectifying action. The work covers forward and reverse bias, junction current, diode characteristics, and how a diode converts alternating current into pulsating direct current through half-wave and full-wave rectification.
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