The distance estimation for which ray optics is good approximation for an aperture of 3 mm and wavelength 300 nm would be:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 30 m
Given:
a = 3 mm = 3 × 10⁻³ m
λ = 300 nm = 3 × 10⁻⁷ m
Calculation:
a²/λ = (3 × 10⁻³)² / (3 × 10⁻⁷)
= 9 × 10⁻⁶ / 3 × 10⁻⁷
= 3 × 10¹
= 30 m