Assertion (A) : The electrical conductivity of a semiconductor increases with increase in temperature.
Reason (R ) : With increase in temperature, large number of electrons from the valence band can jump to the conduction band.

Options

A. (a) If both the statement are TRUE and STATEMENT -2 is the correct explanation of STATEMENT -1
B. (b) If both the statement are TRUE and STATEMENT -2 is NOT the correct explanation of STATEMENT -1
C. (c) If STATEMENT -1 is TRUE and STATEMENT -2 is FALSE
D. (d) If STATEMENT -1 is FALSE and STATEMENT -2 is TRUE

Answer

To solve the assertion-reason question, we will analyze both the assertion (A) and the reason (R) step-by-step.

### Step 1: Understand the Assertion
The assertion states that "The electrical conductivity of a semiconductor increases with an increase in temperature."

**Explanation**:
- In semiconductors, the electrical conductivity is influenced by temperature. As the temperature increases, the thermal energy provided to the electrons increases, allowing more electrons to gain enough energy to jump from the valence band to the conduction band. This results in an increase in the number of charge carriers available for conduction, thereby increasing the conductivity.

### Step 2: Understand the Reason
The reason states that "With an increase in temperature, a large number of electrons from the valence band can jump to the conduction band."

**Explanation**:
- The valence band is the highest energy band that is filled with electrons, while the conduction band is the next higher energy band that is typically empty in semiconductors at low temperatures. The gap between these two bands is called the forbidden energy gap. When the temperature increases, the kinetic energy of the electrons also increases, allowing more electrons to overcome this energy gap and move into the conduction band, thus contributing to electrical conductivity.

### Step 3: Evaluate the Assertion and Reason
- Both the assertion and the reason are correct statements.
- The reason provided explains why the assertion is true: the increase in temperature allows more electrons to jump from the valence band to the conduction band, which in turn increases the electrical conductivity of the semiconductor.

### Conclusion
Since both the assertion and the reason are correct, and the reason is a valid explanation for the assertion, we conclude that the correct answer is that both the assertion and reason are true, and the reason correctly explains the assertion.

### Final Answer
Both Assertion (A) and Reason (R) are correct, and R is the correct explanation of A.

---