Question

The resistivity of an intrinsic semiconductor

• A. increases with an increase in temperature.
• B. decreases with an increase in temperature.
• C. is independent of temperature.
• D. increases upto a certain temperature and thereafter remains constant.

Answer 1

The correct option is B decreases with an increase in temperature.

In an intrinsic semiconductor, there are thermally generated charge carriers i.e. electrons and holes which are very less in number at low temperatures. At room temperature or at high temperature, the number of thermally generated charge carriers increases. As a result, the conductivity of intrinsic semiconductors increases with temperature conductivity $\propto \frac{1}{resistivity}$.
So, resistivity decreases as temperature increases.