In single slit fraunhoffer diffraction which type of wavefront is required-

Options

A. cylindrical
B. spherical
C. elliptical
D. plane

Answer

To determine the type of wavefront required in single slit Fraunhofer diffraction, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Setup**: In a single slit Fraunhofer diffraction experiment, we have a light source that emits waves toward a single slit, which acts as an obstacle.

2. **Position of the Light Source**: The light source is typically placed at an infinite distance from the slit. This means that the rays of light reaching the slit are parallel to each other.

3. **Characteristics of the Wavefront**: Since the rays are parallel, the wavefronts associated with these rays are planar. A plane wavefront is characterized by all points on the wavefront being in phase and having the same distance from the source.

4. **Diffraction Process**: When these parallel rays encounter the slit, they undergo diffraction. The slit allows some of the light to pass through while obstructing the rest, leading to the formation of a diffraction pattern on a screen placed at a distance.

5. **Conclusion**: Given that the rays are parallel due to the infinite distance of the source, the type of wavefront required for single slit Fraunhofer diffraction is a **plane wavefront**.

### Final Answer:
The type of wavefront required in single slit Fraunhofer diffraction is **plane wavefront**.

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