Q. What is the wavelength of light if the first-order maximum occurs at an angle of 30° in a double-slit experiment with slit separation of 0.1 mm and screen distance of 1 m?
A.0.5 mm
B.0.6 mm
C.0.7 mm
D.0.8 mm
Solution
Using d sin θ = mλ, λ = d sin θ/m. For m=1, d=0.1 mm, θ=30°, λ = 0.1 mm * sin(30°) = 0.1 mm * 0.5 = 0.05 mm = 0.5 mm.
