JEE Main20209 Jan 2020Morning ShiftPhysicsWave OpticsActual
The aperture diameter of a telescope is 5 m . The separation between the moon and the earth is 4 × 10 5 k m . With light of wavelength of 5500 Å , the minimum separation between objects on the surface of moon, so that they are just resolved, is close to:
Options
- A60 m
- B20 m
- C200 m
- D600 m
Correct answer
A. 60 m
Step-by-step solution
θ = 1.22 λ a Distance = O 1 O 2 = d θ = 1.22 λ a d Distance = O 1 O 2 = 1.22 × 5893 × 10 - 10 × 4 × 10 8 5 ≈ 57.5 m ∴ answer from options = 60 m (minimum distance)