In a Young's double slit experiment with slit separation 0.1 mm, one observes a bright fringe at angle 1/(40) rad by using light of wavelength λ₁. When the light of wavelength λ₂ is used a bright fringe is seen at the same angle in the same set up. Given that λ₁ and λ₂ are in visible range (380 nm…

Question

In a Young's double slit experiment with slit separation 0.1 mm, one observes a bright fringe at angle 1/(40) rad by using light of wavelength λ₁. When the light of wavelength λ₂ is used a bright fringe is seen at the same angle in the same set up. Given that λ₁ and λ₂ are in visible range (380 nm to 740 nm), their values are

Accepted Answer

(2) 625 nm, 500 nm. Bright fringe: dθ = nλ. dθ = 0.1×10⁻³×1/(40) = 2.5×10⁻⁶ m = 2500 nm. λ = (2500)/n: n=4 gives 625 nm, n=5 gives 500 nm, n=6 gives 417 nm. The pair among the options is 625 nm and 500 nm.

Step-by-step solution

Why the other options are wrong