Statement I: In YDSE, if separation between the slits is less than wavelength of light, then no interference pattern can be observed.
Statement II: For interference pattern to be observed, light sources have to be coherent.

Options

A. Statement I is True, statement II is True, Statement II is a correct explanation for Statement I.
B. Statement I is Ture, Statement II is Ture, Statement II is NOT a correct explanation for Statement I.
C. Statement I is True, Statement II is False.
D. Statement I is False, Statement II is True.

Explanation

To solve the question, we need to analyze the two statements provided:

**Statement I:** In YDSE (Young's Double Slit Experiment), if the separation between the slits is less than the wavelength of light, then no interference pattern can be observed.

**Statement II:** For an interference pattern to be observed, light sources have to be coherent.

### Step-by-Step Solution:

1. **Understanding Statement I:**
- In Young's Double Slit Experiment, the interference pattern is formed due to the superposition of light waves coming from two coherent sources (the slits).
- The condition for observing a clear interference pattern is that the distance between the slits (d) should be comparable to the wavelength of light (λ). If d < λ, the path difference becomes too large, and the resulting interference pattern will not be distinct or may not be observable at all.
- Therefore, Statement I is **correct**: If the separation between the slits is less than the wavelength of light, then no interference pattern can be observed.

2. **Understanding Statement II:**
- Coherent sources are those that maintain a constant phase relationship. For an interference pattern to be stable and observable, the light sources must be coherent.
- If the light sources are not coherent (for example, if they are from different sources or if they are non-monochromatic), the interference pattern will not be clear, and maxima and minima may overlap or appear as a wash of colors rather than distinct bands.
- Thus, Statement II is also **correct**: For an interference pattern to be observed, light sources have to be coherent.

3. **Conclusion:**
- Both statements are correct.
- However, Statement II does not explain Statement I. They are independent statements regarding the conditions for observing interference patterns.

### Final Answer:
Both Statement I and Statement II are correct, but Statement II is not the explanation for Statement I.

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