Question

By increasing the temperature, the specific resistance of a conductor and a semiconductor respectively

• A. increases, increases.
• B. decreases, decreases.
• C. increases, decreases.
• D. decreases, increases.

Hint:

Conductivity is the reciprocal of resistivity; it behaves exactly the opposite.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The question asks about the effect of temperature on the specific resistance (resistivity) of different materials.
Step 2: Detailed Explanation:
1. Conductors: In conductors (metals), as temperature increases, the thermal vibrations of lattice ions increase. This leads to more frequent collisions between free electrons and ions, thereby increasing the resistivity ($\rho$). Thus, specific resistance increases with temperature.
2. Semiconductors: In semiconductors, as temperature increases, more covalent bonds break, leading to a significant increase in the concentration of charge carriers (electrons and holes). This effect dominates over the increased collision frequency, resulting in a net decrease in resistivity. Thus, specific resistance decreases with temperature.
Step 3: Final Answer:
Specific resistance increases for a conductor and decreases for a semiconductor as temperature increases.