In a singleslit diffraction experiment, when a tiny circular obstacle is placed in the path of light from a distant source, a bright spot is seen at the centre of the shadow of the obstacle. Explain why ?
State two points of difference the interference pattern obtained in Young's double slit experiment and the diffraction pattern due to a single slit.

Explanation

### Step-by-Step Solution

1. **Understanding the Setup**: In a single-slit diffraction experiment, a beam of light from a distant source is directed towards a narrow slit. When a tiny circular obstacle is placed in the path of this light, it blocks a portion of the light.

2. **Diffraction of Light**: As light encounters the circular obstacle, it cannot pass through it. However, the edges of the obstacle cause the light waves to bend around it. This bending of light waves is known as diffraction.

3. **Formation of a Shadow**: The area directly behind the obstacle will experience a reduction in light intensity, creating a shadow. However, due to diffraction, some light waves still reach the center of this shadow.

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