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Which of the following statement is/are true?
Statement (S1): Conductivity of silicon is less than that of germanium at room temperature (300 K)
Statement (S2): As the temperature increases, the Fermi level of both N-type and P-type semiconductor materials moves towards the centre of the forbidden energy band gap.
Statement (S1): Conductivity of silicon is less than that of germanium at room temperature (300 K)
Statement (S2): As the temperature increases, the Fermi level of both N-type and P-type semiconductor materials moves towards the centre of the forbidden energy band gap.
- a)Both S1 and S2
- b)Neither S1 nor S2
- c)S1
- d)S2
Correct answer is option 'C'. Can you explain this answer?
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Which of the following statement is/are true?Statement (S1): Conductiv...
- Silicon and germanium both have four valence electrons, but germanium will at a given temperature have more free electrons and a higher conductivity
- Silicon is a widely used semiconductor for electronics because it can be used at much higher temperatures than germanium
- As the temperature increase, more electrons will be moved out from below the Fermi level to above the Fermi level
- If we the temperature the conductivity will increase due to thermal ionisation but the position of Fermi level will not change
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Which of the following statement is/are true?Statement (S1): Conductiv...
Statement (S1): Conductivity of silicon is less than that of germanium at room temperature (300 K)
Silicon and germanium are both semiconductor materials, but their conductivities differ due to their inherent properties. The conductivity of a material depends on its ability to conduct electric current, which is determined by the number of free charge carriers (electrons or holes) available for conduction.
Silicon has a higher bandgap energy (1.12 eV) compared to germanium (0.72 eV). This means that silicon requires more energy to promote its electrons from the valence band to the conduction band, making it less conductive. Germanium, on the other hand, has a lower bandgap energy, allowing its electrons to move more easily from the valence band to the conduction band.
At room temperature (300 K), some electrons in silicon gain enough thermal energy to cross the bandgap and become free charge carriers, contributing to its conductivity. However, since silicon has a higher bandgap energy, fewer electrons are able to overcome this energy barrier, resulting in lower conductivity compared to germanium.
Therefore, Statement (S1) is true.
Statement (S2): As the temperature increases, the Fermi level of both N-type and P-type semiconductor materials moves towards the centre of the forbidden energy band gap.
The Fermi level is a measure of the energy distribution of electrons in a material. In intrinsic (undoped) semiconductors, the Fermi level lies at the middle of the energy band gap. However, in doped semiconductors, such as N-type and P-type materials, the Fermi level shifts towards the energy band of the majority charge carriers.
In N-type semiconductors, the majority charge carriers are electrons, and the Fermi level is close to the conduction band. As temperature increases, more electrons are thermally excited from the valence band to the conduction band, increasing the electron concentration. This leads to a shift in the Fermi level towards the centre of the band gap.
In P-type semiconductors, the majority charge carriers are holes, and the Fermi level is close to the valence band. As temperature increases, more holes are thermally excited from the valence band to the conduction band, increasing the hole concentration. This also causes a shift in the Fermi level towards the centre of the band gap.
Therefore, Statement (S2) is false.
In conclusion, only Statement (S1) is true.
Silicon and germanium are both semiconductor materials, but their conductivities differ due to their inherent properties. The conductivity of a material depends on its ability to conduct electric current, which is determined by the number of free charge carriers (electrons or holes) available for conduction.
Silicon has a higher bandgap energy (1.12 eV) compared to germanium (0.72 eV). This means that silicon requires more energy to promote its electrons from the valence band to the conduction band, making it less conductive. Germanium, on the other hand, has a lower bandgap energy, allowing its electrons to move more easily from the valence band to the conduction band.
At room temperature (300 K), some electrons in silicon gain enough thermal energy to cross the bandgap and become free charge carriers, contributing to its conductivity. However, since silicon has a higher bandgap energy, fewer electrons are able to overcome this energy barrier, resulting in lower conductivity compared to germanium.
Therefore, Statement (S1) is true.
Statement (S2): As the temperature increases, the Fermi level of both N-type and P-type semiconductor materials moves towards the centre of the forbidden energy band gap.
The Fermi level is a measure of the energy distribution of electrons in a material. In intrinsic (undoped) semiconductors, the Fermi level lies at the middle of the energy band gap. However, in doped semiconductors, such as N-type and P-type materials, the Fermi level shifts towards the energy band of the majority charge carriers.
In N-type semiconductors, the majority charge carriers are electrons, and the Fermi level is close to the conduction band. As temperature increases, more electrons are thermally excited from the valence band to the conduction band, increasing the electron concentration. This leads to a shift in the Fermi level towards the centre of the band gap.
In P-type semiconductors, the majority charge carriers are holes, and the Fermi level is close to the valence band. As temperature increases, more holes are thermally excited from the valence band to the conduction band, increasing the hole concentration. This also causes a shift in the Fermi level towards the centre of the band gap.
Therefore, Statement (S2) is false.
In conclusion, only Statement (S1) is true.
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Which of the following statement is/are true?Statement (S1): Conductivity of silicon is less than that of germanium at room temperature (300 K)Statement (S2): As the temperature increases, the Fermi level of both N-type and P-type semiconductor materials moves towards the centre of the forbidden energy band gap.a)Both S1 and S2b)Neither S1 nor S2c)S1d)S2Correct answer is option 'C'. Can you explain this answer?
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Which of the following statement is/are true?Statement (S1): Conductivity of silicon is less than that of germanium at room temperature (300 K)Statement (S2): As the temperature increases, the Fermi level of both N-type and P-type semiconductor materials moves towards the centre of the forbidden energy band gap.a)Both S1 and S2b)Neither S1 nor S2c)S1d)S2Correct answer is option 'C'. Can you explain this answer? for Railways 2024 is part of Railways preparation. The Question and answers have been prepared according to the Railways exam syllabus. Information about Which of the following statement is/are true?Statement (S1): Conductivity of silicon is less than that of germanium at room temperature (300 K)Statement (S2): As the temperature increases, the Fermi level of both N-type and P-type semiconductor materials moves towards the centre of the forbidden energy band gap.a)Both S1 and S2b)Neither S1 nor S2c)S1d)S2Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for Railways 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Which of the following statement is/are true?Statement (S1): Conductivity of silicon is less than that of germanium at room temperature (300 K)Statement (S2): As the temperature increases, the Fermi level of both N-type and P-type semiconductor materials moves towards the centre of the forbidden energy band gap.a)Both S1 and S2b)Neither S1 nor S2c)S1d)S2Correct answer is option 'C'. Can you explain this answer?.
Which of the following statement is/are true?Statement (S1): Conductivity of silicon is less than that of germanium at room temperature (300 K)Statement (S2): As the temperature increases, the Fermi level of both N-type and P-type semiconductor materials moves towards the centre of the forbidden energy band gap.a)Both S1 and S2b)Neither S1 nor S2c)S1d)S2Correct answer is option 'C'. Can you explain this answer? for Railways 2024 is part of Railways preparation. The Question and answers have been prepared according to the Railways exam syllabus. Information about Which of the following statement is/are true?Statement (S1): Conductivity of silicon is less than that of germanium at room temperature (300 K)Statement (S2): As the temperature increases, the Fermi level of both N-type and P-type semiconductor materials moves towards the centre of the forbidden energy band gap.a)Both S1 and S2b)Neither S1 nor S2c)S1d)S2Correct answer is option 'C'. Can you explain this answer? covers all topics & solutions for Railways 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Which of the following statement is/are true?Statement (S1): Conductivity of silicon is less than that of germanium at room temperature (300 K)Statement (S2): As the temperature increases, the Fermi level of both N-type and P-type semiconductor materials moves towards the centre of the forbidden energy band gap.a)Both S1 and S2b)Neither S1 nor S2c)S1d)S2Correct answer is option 'C'. Can you explain this answer?.
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