Answer: 100.
- A 50
- B 100
- C 40
- D 2000
Correct answer: B. 100
Explanation: β = I<sub>C</sub>/I<sub>B</sub> = 2 mA / 20 μA = 2000 μA / 20 μA = 100.
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.