Question

State the essential condition for diffraction of light to occur

Answer 1

It only when dimension of obstraclce is comparable with wavelength of wave

Answer 2

Condition of diffraction:- Size of obstacle in other words aperture must br almost equal to the wavelength of light.

Second condition is that size of obstacle to be much greater to wavelength of light, then rectilinear motion will be observed.

Special Points:-

1. The obstacle or aperature does not shows diffraction.

2. Wavelength of light is of the order 10^-7 m.

3. In general obstacle of this wavelength is not present so light rays does not show diffraction.

4. It appears to travel in straight line Sound wave shows more diffraction as compared to ight rays because wavelength of sound is large.