Question

Two materials $\text{Si}$ and $\text{Cu}$, are cooled from $300\text{K}$ to $60\text{K}$. What will be the effect on their resistivity ?

​​​​​​​$[$1 Mark$]$

• A. Resistivity of both $\text{Si}$ and $\text{Cu}$ increases
• B. Resistivity of $\text{Si}$ increases and resistivity of $\text{Cu}$ decreases
• C. Resistivity of both $\text{Si}$ and $\text{Cu}$ decreases
• D. Resistivity of $\text{Si}$ decreases and resistivity of $\text{Cu}$ increases

Answer 1

The correct option is B Resistivity of $\text{Si}$ increases and resistivity of $\text{Cu}$ decreases

Variation of resistivity $\left(S\right)$ with temperature $\left(T\right)$ for $\text{Si}$ $\text{(semiconductor)}$ is given by

It is clear that on decreasing the temperature, the resistivity of $\text{Si}$ increases

Variation of resistivity $\left(S\right)$ with temperature $\left(T\right)$ for $\text{Cu}$ $\text{(conductor)}$ is given by


It is clear that on decreasing the temperature, the resistivity of $\text{Cu}$ decreases