Answer: Forward bias only.
- A Reverse bias only
- B Forward bias only
- C Both directions equally
- D Neither direction
Correct answer: B. Forward bias only
Explanation: P-n junction diode allows easy current flow in forward bias; reverse bias blocks current (only tiny leakage).
Conductors have overlapping bands, semiconductors have a small energy gap that can be bridged by heat or doping, and insulators have a large gap that blocks conduction.
Concept context
Band theory, p-n junction, diodes, transistors, logic gates, and integrated circuits.