In Fresnel's class of diffraction the

Options

A. obstacle screen distance is finite
B. the diffracted wavefront is considered as spherical
C. no convex lens is used to focus the diffraction fringes on the screen
D. All of the above

Answer

D

Explanation

In Fresnel's class of diffraction the source of light and the screen on which the diffraction pattern in observed are at finite distance from diffracting obstacle. In this no lenses are used and the incident wavefrom is either spherical or cylindrical