Question

The mobility of charge carriers increases with

• A. Increase in the average collision time
• B. Increase in the electric field
• C. Increase in the mass of the charge carriers
• D. Decrease in the charge of the mobile carriers

Answer 1

The correct option is A

Increase in the average collision time

Explanation for correct option:

Mobility:

1. It is defined as the net average velocity with which the free-electrons move toward the positive end of a conductor under the influence of an applied electric field.
2. Mobility is given as,

$\mu =\frac{qt}{m}$

Where $q$ is the charge of the carrier, $t$ is the average collision time and $m$ is mass of the charge carrier.

3. From the equation of mobility, it is clear that,

$\mu \propto t$ since charge and mass are constants

i.e., the mobility of the charge carrier is directly proportional to the increase in average collision time.

Hence, option (A) is the correct option.