1. Understand what is being asked

We need the effect of increasing temperature on the specific resistance (resistivity) of:

• a conductor
• a semiconductor

2. For a conductor

In conductors, as temperature increases, lattice vibrations increase. This causes more collisions for free electrons, so the resistivity increases.

Thus, $\rho_{\text{conductor}} \uparrow \text{ with temperature}$

3. For a semiconductor

In semiconductors, as temperature increases, more charge carriers (electrons and holes) are generated.

So conductivity increases, and hence resistivity decreases.

Thus, $\rho_{\text{semiconductor}} \downarrow \text{ with temperature}$

4. Match with the options

• A: increases for both $\rightarrow$ wrong
• B: decreases for both $\rightarrow$ wrong
• C: increases, decreases $\rightarrow$ correct
• D: decreases, increases $\rightarrow$ wrong

5. Final answer

The specific resistance:

• increases for a conductor
• decreases for a semiconductor

So the correct option is C.