Question

Which graph is shown in the figure?

(a) Amplitude variation with the number of exposed zones

(b) Intensity variation with the number of exposed zones

(c) Frequency variation with the number of exposed zones

(d) Phase variation with the number of exposed zones

The question was asked in quiz.

My query is from Fresnel Diffraction topic in section Optics of Engineering Physics II

Answer 1

The correct choice is (b) Intensity variation with the number of exposed zones

Explanation: The figure shows the variation of intensity with the number of exposed zones. We know, the resultant intensity at O is \(\frac{m_1^2}{4}\). Only the first half period zone is effective in producing the illumination at O.