question_answer

In a Young's double slit experiment 10 fringes are observed in a given segment of the screen when light of wavelength 500.0 nm is used. When the experiment is performed in a medium of refractive index 1.2, the number of fringes observed in the same segment remains 10. The wavelength of light used in this case is

A) 400.0 nm

B) 417.7nm

C) 500.0nm

D) 600.0nm