Answer: Perfect insulator.
- A Good conductor
- B Perfect insulator
- C Semiconductor
- D Superconductor
Correct answer: B. Perfect insulator
Explanation: At 0 K, all bonds are intact, no free carriers. Intrinsic semiconductor acts as a perfect insulator at absolute zero.
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.