The main condition for diffraction to be observed is

Options

A. size of obstacle should be comparable to the wavelength of the wave
B. size of obstacle should be much larger than the wavelength of the wave
C. size of obstacle should be much smaller than the wavelength of the wave
D. for any size of obstacle

Answer

To determine the main condition for diffraction to be observed, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Diffraction**:
- Diffraction is a phenomenon that occurs when a wave encounters an obstacle or a slit that is comparable in size to its wavelength. This causes the wave to bend around the obstacle or spread out after passing through the slit.

2. **Identifying Key Factors**:
- The key factors that influence diffraction include the wavelength of the wave and the size of the obstacle or aperture.

3. **Establishing the Condition**:
- For diffraction to be observed, the wavelength of the wave must be comparable to the size of the obstacle or the aperture through which the wave is passing. This means that the wavelength should not be significantly smaller or larger than the dimensions of the object.

4. **Conclusion**:
- Therefore, the main condition for diffraction to be observed is that the wavelength of the wave should be comparable to the size of the object or aperture.

### Final Answer:
The main condition for diffraction to be observed is that the wavelength of the wave should be comparable to the size of the object.

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