Question

Read the following statements carefully:
Y: The resistivity of a semiconductor decreases with the increase of temperature. Z: In a conduction solid, rate of collision between free electrons and ions increases with the increase of temperature.

Select the correct statement(s) from the following.

• A. Y is true but z is false
• B. Y is false but z is true
• C. Both y and z are true
• D. Y is true and z is correct reason for y

Answer 1

Answer: (C), (D)

The correct options are
C Y is true and z is correct reason for y
D Both y and z are true

In case of semiconductor $Resistivity\alpha \frac{1}{temperature}$

In this case as temperature increases electrons jump to conduction band resistance decreases $R\alpha \rho \left(Resistivity\right)$ so resistivity also decreases and current increases.

Vibration of electrons increases with rise in temperature and hence collision between ions and electrons increases with temperature.