In a Young's double slit experiment, 10 fringes are observed in a given segment of the screen when light of wavelength 600 nm is used. When this light is replaced by another monochromatic source, the number of fringes in the same segment of the screen increases by 5 . The wavelength of the new light source is:

Step-by-step solution

The length of the segment on the screen remains constant. The total width of n fringes is given by y = n = n ( D d ) . Since y , D , and d are constant, n 1 , which gives n₁ ₁ = n₂ ₂ . The initial number of fringes is n₁ = 10 and the initial wavelength is ₁ = 600 nm . The number of fringes increases by 5 , so the new number of fringes is n₂ = 10 + 5 = 15 . Substituting these values into the relation: 10 600 = 15 ₂ ₂ = 6000 15 = 400 nm . Answer: 400 nm