Question:
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 the effect of a decrease in relaxation time is much less than the increase in number density
Solution:
(d) number density of current carriers increases, relaxation time decreases but the effect of a decrease in relaxation time is much less than the increase in number density