Q127 / 180 · KCET 2019 · Physics
The conductivity of semiconductor increases with increase in temperature because
- Aboth number density of charge carriers and relaxation time increase
- Bnumber density of charge carriers increases
- Correct answerCnumber density of current carriers increases, relaxation time decreases but effect of
decrease in relaxation time is much less than increase in number density - Drelaxation time increases
Solution
(C)
As temperature increases the number density of charge carries increases according to the equation \( \mathrm{n}=C T^{\frac{3}{2}} \cdot \exp \)
\( \left(-\frac{E}{2} k T\right) \). Thus as temperature increases, the number density of charge carries increase resulting in conductivity
ofsemiconductors.
As temperature increases the number density of charge carries increases according to the equation \( \mathrm{n}=C T^{\frac{3}{2}} \cdot \exp \)
\( \left(-\frac{E}{2} k T\right) \). Thus as temperature increases, the number density of charge carries increase resulting in conductivity
ofsemiconductors.
Hence, the correct answer is option: 'C'.