If Fraunhofer diffraction experiment, L is the distance between screen and the obstacle, b is the size of obstacle and X is wavelength of incident light. The general condition for the applicability of Fraunhofer diffraction is

Options

A. `b^(2)/(L lambda) gt gt 1`
B. `b^(2)/(L lambda) = 1`
C. `b^(2)/(L lambda) lt lt 1`
D. `b^(2)/(L lambda) ne 1`

Answer

c

Explanation

`If b^(2)/(llambda) gtgt 1`, then the approximation of geometrical optics is applicable.
`If b^(2)/(llambda) 1`hen Fresnel diffraction is observed
`If b^(2)/(llambda) ltlt 1`, then Fraunhofer diffraction is observed.