The forbidden energy band gaps in conductors, semiconductors and insulators are \(EG_{1},\) \(EG_{2}\) and \(EG_{3}\) respectively. The relation among them is:
1. \(EG_{1}=EG_{2}=EG_{3}\)
2. \(EG_{1}<EG_{2}<EG_{3}\)
3. \(EG_{1}>EG_{2}>EG_{3}\)
4. \(EG_{1}<EG_{2}>EG_{3}\)
Subtopic:  Energy Band theory |
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Level 1: 80%+
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Choose the only false statement from the following.

1. The resistivity of a semiconductor increases with an increase in temperature.
2. Substances with an energy gap of the order of \(10~\text{eV}\) are insulators. 
3. In conductors, the valence and conduction bands may overlap.
4. The conductivity of a semiconductor increases with an increase in temperature.
Subtopic:  Energy Band theory |
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The electrical conductivity of a semiconductor increases when electromagnetic radiation with a wavelength shorter than \(2400~\text{nm}\) is incident on it. The band gap of the semiconductor (in eV) is: \((h=6.63\times10^{-34}~\text{J-s})\)
1. \(0.33\) eV 2. \(0.80\) eV
3. \(0.52\) eV 4. \(0.10\) eV
Subtopic:  Energy Band theory |
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Level 2: 60%+
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The maximum wavelength of electromagnetic radiation, which can create hole-electron pairs in semiconductor is:
(Given that the forbidden energy gap in the semiconductor is \(0.5~\text{eV}\)
1. \(2.48 \times 10^{-7}~\text{m} \)
2. \(2.48 \times 10^{-6}~\text{m} \)
3. \(2.48 \times 10^{-8}~\text{m}\)
4. \(2.48 \times 10^{-9}~\text{m}\)
Subtopic:  Energy Band theory |
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Level 2: 60%+
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