Assuming that the human pupil has a radius of 0.25 cm and a comfortable viewing distance of 25 cm . The minimum separation between two point objects that the human eye can resolve for the light of wavelength 500 nm is

Step-by-step solution

By fraunhofer diffraction through a circular aperture, θ = 1.22 λ d d = diameter of pupil = 2 × 0.25 = 0.5 cm λ = 500 nm First dark ring is formed by the light diffracted from the hole at an angle θ with the axis. Viewing distance, D = 25 cm ∴ Minimum separation between 2 objects = Dθ = 25 × 10 - 2 × 1.22 × 500 × 10 - 9 5 × 10 - 1 = 30 × 10 - 6 m = 30 μm