Write two points of difference between interference and diffraction pattern of light.

Options

A. diffraction is due to interaction of light from the same wavefront, whereas the interference is the interaction of waves from two isolated sources
B. diffraction is due to interaction of light from the same wavefront, whereas the interference is the interaction of two waves derived from the same source
C. diffraction is due to interaction of waves derived from the same source, whereas the interference is the bending of light from the same wavefront
D. diffraction is caused by the reflected waves from a source, whereas interference is caused due to refraction of waves from a source

Answer

To differentiate between interference and diffraction patterns of light, we can outline two key points:

1. **Source of Waves**:
- **Interference**: It occurs due to the interaction of waves from two coherent sources. Coherent sources are those that maintain a constant phase relationship, which is essential for producing a stable interference pattern.
- **Diffraction**: It is caused by the bending and spreading of waves when they encounter an obstacle or slit that is comparable in size to their wavelength. This phenomenon can occur with waves from a single source or wavefront.

2. **Nature of the Pattern**:
- **Interference**: The interference pattern consists of alternating bright and dark fringes due to constructive and destructive interference of light waves. The pattern is typically observed when two coherent light sources overlap.
- **Diffraction**: The diffraction pattern is characterized by a series of light and dark regions that result from the bending of waves around obstacles or through slits. The pattern is generally more complex and can vary based on the size and shape of the aperture or obstacle.