Answer:
691.13 nm
Explanation:
d = width of the slit = 0.11 x 10⁻³ m
θ = angle of diffraction pattern = 0.72° degree
λ = wavelength of the light = ?
m = order = 2 (since second minimum)
for the second minimum diffraction pattern we use the equation
d Sinθ = m λ
Inserting the values
(0.11 x 10⁻³) Sin0.72 = (2) λ
λ = 691.13 x 10⁻⁹ m
λ = 691.13 nm
