A parallel beam of light of wavelength is incident normally on a narrow slit. A diffraction pattern is formed on a screen placed perpendicular to the direction of the incident beam. At the second minimum of the diffraction pattern, the phase difference between the rays coming from the two edges of slit is
- 2
- 3
- 4
Answer
(3) 4
Solution
For the nth minimum of single-slit diffraction: a = n
Second minimum (n = 2): path difference between the edge rays = 2
Phase difference = 2 2 = 4
Answer: (3)