List of top Physics Questions on Wave optics asked in SRMJEEE

Which among the following statements is true about Hugen’s principle

Which of the following phenomenon is not explained by Huygen’s wave theory?

X-rays of wavelength 1.14 A in the first order reflection from a crystal, were reflected at an angle of 30^o.
The inter planar distance in the crystal is (Sin 30^ois 0.5)

Huygen's principle of secondary waves is used to