Chapter 29, Problem 40A

To determine

To explain why on heating a semiconductor its conductivity increases.

Answer to Problem 40A

As conductivity is directly proportional to the temperature, therefore, as the temperature increases on heating, conductivity also increases.

Explanation of Solution

Introduction: The conductivity of a semiconductor increases on heating.

Conductivity of a semiconductor depends upon two factors, the concentration of free carriers available to conduct current and their mobility. Both mobility and carrier concentration are temperature dependent. Thus, the conductivity can be expressed as a function of temperature, where is the conductivity and T is the temperature.

Conclusion: As conductivity is directly proportional to the temperature, therefore, as the temperature increases on heating, conductivity also increases.