A plane wave that falls on a barrier containing small circular opening of dimension d. What can be said about the behaviour of the wave if `(i) lamda lt lt d, (ii) lamda = d ,(iii) lamda gt gt d `

Explanation

To analyze the behavior of a plane wave that falls on a barrier with a small circular opening of dimension \( d \), we will consider three different scenarios based on the relationship between the wavelength \( \lambda \) and the dimension \( d \) of the opening.

### Step-by-Step Solution:

1. **Case (i): \( \lambda \ll d \) (Wavelength much smaller than the aperture dimension)**
- When the wavelength is much smaller than the aperture dimension, the wave behaves almost like a ray. The wavefronts pass through the opening with minimal diffraction. The majority of the wave energy continues in the original direction, and the diffraction effects are negligible.
- **Conclusion**: The wave will pass through the opening with little to no diffraction.

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