Conductivity will increase with temperature in :

Options

A. metal
B. non-metal
C. semiconductor
D. None of these

Answer

To solve the question "Conductivity will increase with temperature in:", we need to analyze the behavior of different materials (metals, non-metals, semiconductors) with respect to temperature and conductivity.

### Step-by-Step Solution:

1. **Understanding Conductivity**:
- Conductivity is the ability of a material to conduct electric current. It is influenced by the number of charge carriers (electrons or holes) available in the material.

2. **Behavior of Metals**:
- In metals, as the temperature increases, the lattice vibrations of the metal ions increase. This leads to more collisions between the conduction electrons and the vibrating ions, which actually decreases the conductivity. Therefore, conductivity in metals decreases with an increase in temperature.

3. **Behavior of Non-Metals**:
- Non-metals generally have very low conductivity. Their conductivity does not significantly increase with temperature, and in many cases, it remains constant or decreases.

4. **Behavior of Semiconductors**:
- Semiconductors, such as silicon or germanium, have a unique property. At low temperatures, they have very few charge carriers, leading to low conductivity. However, as the temperature increases, more charge carriers (electrons and holes) are generated due to thermal excitation. This results in an increase in conductivity with temperature.

5. **Conclusion**:
- Based on the analysis, the material whose conductivity increases with temperature is the semiconductor.

### Final Answer:
Conductivity will increase with temperature in **semiconductors**.