Why in Newton’s rings the center spot is always dark?
A. The thickness of the film is zero at center
B. The path difference between incident ray and reflected ray is ½wavelength C. The incident ray and reflected ray undergo destructive interference D. All of above
A. The thickness of the film is zero at center
B. The path difference between incident ray and reflected ray is ½wavelength C. The incident ray and reflected ray undergo destructive interference D. All of above