# The temperature dependence of resistances of

Question:

The temperature dependence of resistances of $\mathrm{Cu}$ and undoped Si in the temperature range 300 $400 \mathrm{~K}$, is best described by :-

1. Linear decrease for $\mathrm{Cu}$, linear decrease for Si.

2. Linear increase for $\mathrm{Cu}$, linear increase for Si.

3. Linear increase for $\mathrm{Cu}$, exponential increase for $\mathrm{Si}$

4. Linear increase for $\mathrm{Cu}$, exponential decrease for $\mathrm{Si}$

Correct Option: , 4

Solution:

Factual

$\mathrm{Cu}$ is conductor so with increase in temperature, resistance will increase Si is semiconductor so with increase in temperature resistance will decrease