As the temperature increases, resistivity of semi-conductor:

Options

A. increases
B. decreases
C. independent
D. increases exponentially

Explanation

To solve the question regarding the relationship between temperature and resistivity in semiconductors, we can follow these steps:

### Step 1: Understand the Concept of Resistivity
Resistivity is a measure of how strongly a material opposes the flow of electric current. In semiconductors, resistivity is influenced by the number of charge carriers (electrons and holes) available for conduction.

**Hint:** Remember that resistivity is inversely related to conductivity.

### Step 2: Analyze the Effect of Temperature on Semiconductors
As the temperature of a semiconductor increases, the thermal energy provided to the electrons also increases. This additional energy allows more electrons to jump from the valence band to the conduction band.

**Hint:** Consider how thermal energy affects the movement of electrons in a semiconductor.

### Step 3: Determine the Change in Charge Carriers
When more electrons jump to the conduction band, the number of charge carriers (electrons) available for conduction increases. This increase in charge carriers leads to higher conductivity.

**Hint:** Think about how the number of available charge carriers affects the overall conductivity of the material.

### Step 4: Relate Conductivity to Resistivity
Since conductivity increases with the increase in temperature, the resistivity, which is the inverse of conductivity, must decrease.

**Hint:** Remember the relationship: \( \text{Resistivity} = \frac{1}{\text{Conductivity}} \).

### Step 5: Conclusion
As a result of the increased temperature, the resistivity of the semiconductor decreases. Therefore, the correct answer to the question is that the resistivity of a semiconductor decreases as the temperature increases.

**Final Answer:** The resistivity of a semiconductor decreases as the temperature increases.