Question

On increasing the temperature of a conductor, its resistance increases because

• A. Relaxation time decreases
• B. Mass of the electrons increases
• C. Electron density decreases
• D. None of the above

Answer 1

Answer: (A)

Relaxation time decreases

Answer 2

Resistance of conductor depends upon relation as $R \propto \frac{1}{\tau}$. With rise in temperature rms speed of free electron inside the conductor increase, so relaxation time decrease and hence resistance increases