Question

The aperture diameter of a telescope is 5m. The separation between the moon and the earth is 4 × 10 5 km. 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 :

(1) 20 m

(2) 600 m

(3) 60 m

(4) 200 m 

Answer 1

Answer is (3) 60 m

Let distance is x then

most appropriate is 60m

Answer 2

answer from options = 60 m

minimum distance