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CUET
Physics
Ray Optics
The distance estimation for which ray optics is good approximation for an aperture of 3 mm and wavelength 300 nm would be:
40 m
30 m
20 m
10 m
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
