# In a young’s double slit experiment with slit separation 0.1 mm, one observes a bright fringe at angle   rad by using light of wavelength . When the light of wavelength  is used a bright fringe is seen at the same angle in the same set up. Given that  and  are in visible range (380 nm to 740 nm), their values are (a) 380 nm, 500 nm (b) 625 nm, 500 nm (c) 380 nm, 525 nm (d) 400 nm, 500 nm

## Question ID - 50224 | SaraNextGen Top Answer In a young’s double slit experiment with slit separation 0.1 mm, one observes a bright fringe at angle   rad by using light of wavelength . When the light of wavelength  is used a bright fringe is seen at the same angle in the same set up. Given that  and  are in visible range (380 nm to 740 nm), their values are (a) 380 nm, 500 nm (b) 625 nm, 500 nm (c) 380 nm, 525 nm (d) 400 nm, 500 nm

Answer Key / Explanation : (b) -

Path difference=d

=0.1 mm=2500nm

Or bright fringe, path difference must be integral multiple of λ.

2500=n =

=625, =500 (from m=5)

(for n=4)