In a semiconductor let the number of charge carriers be n and the average drift speed be v. An electric field is applied to it. If we increase the temperature of this semiconductor then:

n will increase but v will decrease

The correct answer is Option (1) → n will increase but v will decrease

As we increase the temperature, additional electron -hole pairs are created in the semiconductor.

As a result, number of charge carrier (n) increases.

Now,

$v_d=\frac{eEZ}{m}$

and, Temperature ∝ $\frac{1}{Z}$

∴ Temperature ∝ $\frac{1}{v_d}$

Hence, $v_d$ decreases