Question

state the essential condition for diffraction of light

Answer 1

ANSWER

The condition is "the width of obstacle or aperture must be less than or comparable with wavelength of light used."

Diffraction effect depends upon the size of obstacle. Diffraction of light takes place if the size of obstacle is comparable to the wavelength of light.

Light waves are very small in wavelength, i.e. from 4 x 10-7 m to 7 x 10-7 m. If the size of opening or obstacle is near to this limit, only then we can observe the phenomenon of diffraction.

Answer 2

The condition is "the width of obstacle must be less than or comparable with wavelength of light used." Diffraction effect depends upon the size of obstacle.