Question

When a p-n junction diode is in forward bias, which type of charge carriers flows in the connecting wire?

• A. Ions
• B. Protons
• C. Holes
• D. Free electrons

Answer 1

The Correct Option is D

In a p-n junction diode under forward bias, the charge carriers responsible for current flow in the external circuit are free electrons. These electrons are present in the n-type material, and they move towards the p-type material. The free electrons from the n-side travel through the external circuit to the p-side, where they recombine with holes. This flow of free electrons constitutes the current in the connecting wire.

Answer 2

In a forward-biased p-n junction diode, the electrons from the n-side and the holes from the p-side move toward the junction. However, in the external connecting wire, the current is due to the movement of \(\textbf{free electrons}\), as electrons are the actual charge carriers in metal conductors (wires). Holes contribute to current only within the semiconductor, not in the external circuit.