Solution:
[Concept]: Path difference at S2 is . Therefore for minimum intensity(dark band) at P.
Solving equation,
Two coherent point sources vibrating in phase emit light of wavelength . The separation between the sources is . The smallest distance from on a line passing through and perpendicular to , where a minimum of intensity occurs is:
[Concept]: Path difference at S2 is . Therefore for minimum intensity(dark band) at P.
Solving equation,