The average distance between the earth and moon is `3.86xx10^(4)km`. The minimum separation between the two points on the surface of the moon that can be resolved by a telescope whose objective lens has a diameter os `5 m` with `lambda=6000 Å` is

Options

A. `5.65 m`
B. `28.25 m`
C. `11.30 m `
D. `56.51 m`

Answer

D

Explanation

Resolving power`=(1.22lambda)/(a)=(1.22 xx6000xx10^(-10))/(5)`
Also resolving power `=(d)/(D)=(d)/(38.6xx10^(7))`
`:. (1.22xx6xx10^(-7))/(5)=(d)/(38.6xx10^(7))`
`impliesd=(1.22xx6xx10^(-7)xx38.6xx10^(7))/(5)m=56.51m`