Statement-I : In Young's double slit experiment interference pattern dissappears when one of the slits is closed
Statement-II : Interference is observed due to superposition of light waves from two coherent source

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Explanation

To analyze the given statements regarding Young's double slit experiment, we can break down the solution step by step:

### Step 1: Understand Statement-I
Statement-I states that "In Young's double slit experiment, the interference pattern disappears when one of the slits is closed."

**Explanation**: In Young's double slit experiment, interference patterns are formed due to the superposition of light waves coming from two coherent sources (the two slits). If one of the slits is closed, there is only one source of light wave available. As a result, there will be no superposition of two waves, leading to the disappearance of the interference pattern.

### Step 2: Understand Statement-II
Statement-II states that "Interference is observed due to the superposition of light waves from two coherent sources."

**Explanation**: This statement is true because interference occurs when two or more coherent light waves overlap and combine. The condition for interference is that the light waves must be coherent, meaning they have a constant phase difference. The superposition principle states that when two waves meet, the resultant wave is the sum of the individual waves.

### Step 3: Evaluate the Truth of the Statements
- **Statement-I** is true because closing one slit eliminates one of the coherent sources necessary for interference.
- **Statement-II** is also true as it correctly describes the condition for interference.

### Step 4: Determine the Relationship Between the Statements
Statement-II provides a correct explanation for Statement-I. The interference pattern disappears when one slit is closed because there are no longer two coherent sources to produce the interference.

### Conclusion
Both statements are true, and Statement-II is the correct explanation for Statement-I. Therefore, the answer is that both statements are true, and Statement-II explains Statement-I.

### Final Answer
Both Statement-I and Statement-II are true, and Statement-II is the correct explanation of Statement-I.

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