The aperrture of the largest telescope in the world is about 5 m. if the separation between the moon and the earth is `4xx10^(5)km` and the wavelength of visible light is 5000 Å, then the minimum separation between the objects on the surface of the moon which can be just resolved is approximately equal to

Options

A. 200 m
B. 100 m
C. 50 m
D. 25 m

Answer

C

Explanation

`d theta=`angle of the once of light from the objects
`d theta=("diameter of the telescope")/("distance of the moon")=(5)/(4xx10^(5)xx10^(3)m)`
`therefore d theta=(1.22lamda)/(D)`
`therefore D=48.8mm ~~50m`