Question

Mobility of free electrons in a conductor is

• A. directly proportional to electron density.
• B. directly proportional to relaxation time.
• C. inversely proportional to electron density.
• D. inversely proportional to relaxation time.

Answer 1

Answer: (B)

directly proportional to relaxation time.

Answer 2

Key Idea Electron mobility $\propto$ Drift velocity. Mobility of free electrons in a conductor is directly proportional to relaxation time. $\mu \propto \tau$