- 1(current)
Q. No.What is the conductivity of a semiconductor sample having electron concentration of \(5\times10^{18}~\text{m}^{-3},\) hole concentration of \(5\times10^{19}~\text{m}^{-3},\) electron mobility of \(2.0~\text{m}^2~\text{V}^{-1}\text{s}^{-1}\) and hole mobility of \(0.01~\text{m}^2\text{V}^{-1}~\text{s}^{-1}?\)
(Take charge of an electron as \(1.6\times10^{-19}~\text{C})\)
1. \(0.59~(\Omega\text-\text{m})^{-1}\)
2. \(1.20~(\Omega\text-\text{m})^{-1}\)
3. \(1.68~(\Omega\text-\text{m})^{-1}\)
4. \(1.83~(\Omega\text-\text{m})^{-1}\)
(Take charge of an electron as \(1.6\times10^{-19}~\text{C})\)
1. \(0.59~(\Omega\text-\text{m})^{-1}\)
2. \(1.20~(\Omega\text-\text{m})^{-1}\)
3. \(1.68~(\Omega\text-\text{m})^{-1}\)
4. \(1.83~(\Omega\text-\text{m})^{-1}\)
Subtopic: Â Energy Band theory |
 63%
From NCERT
JEE
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Hints
An LED is constructed from \(\mathrm{Ga\text-As\text-P}\) semiconducting material with an energy gap of \(1.9~\text{eV}.\) What is the wavelength of the emitted light and what colour does it correspond to?
(take \(h=6.63\times10^{-34}~\text{J-s}\) and \(c=3\times10^8~\text{m/s}\))
| 1. | \(1046~\text{nm}\) and red colour |
| 2. | \(654~\text{nm}\) and orange colour |
| 3. | \(1046~\text{nm}\) and blue colour |
| 4. | \(654~\text{nm}\) and red colour |
Subtopic: Â Energy Band theory |
From NCERT
JEE
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Hints
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The energy band gap of semiconducting material to produce violet (wavelength \(=4000~\mathring{A}\)) LED is (nearly):
1. \(3~\text{eV}\)
2. \(5~\text{eV}\)
3. \(1~\text{eV}\)
4. \(7~\text{eV}\)
1. \(3~\text{eV}\)
2. \(5~\text{eV}\)
3. \(1~\text{eV}\)
4. \(7~\text{eV}\)
Subtopic: Â Energy Band theory |
 88%
From NCERT
JEE
To view explanation, please take trial in the course.
NEET 2026 - Target Batch - Vital
Hints
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NEET 2026 - Target Batch - Vital
The acceptor level of a p-type semiconductor is \(6\) eV. The maximum wavelength of light which can create a hole would be : Given \(h c=1242\) eV-nm.
1. \(407\) nm
2. \(207\) nm
3. \(103.5\) nm
4. \(414\) nm
Subtopic: Â Energy Band theory |
 86%
JEE
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Hints
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Q. No.
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