COMEDK · Physics · 30. Semiconductors
The conductivity of a semiconductor increases with increase in temperature because
A) number density of free current carriers increases
B) relaxation time increases
C) both number density of carriers and relaxation time increase
D) number density of current carriers increases, relaxation time decreases but effect of decrease in relaxation time is much less than increase in number density
- A B
- B D
- C C
- D A
Answer & Solution
Correct Answer
(B) D
Step-by-step Solution
Detailed explanation
The conductivity \(\sigma\) of a semiconductor is given by the relation \(\sigma = e(n_e \mu_e + n_h \mu_h)\), where \(n_e\) and \(n_h\) are the number densities of electrons and holes, and \(\mu_e\) and \(\mu_h\) are their respective mobilities. As temperature increases, the…
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