An astronaut is looking down on earth's surface from a space shuttle at an altitude of `400 km. ` Assuming that the astronaut's pupil diameter is `5 mm` and the wavelength of visible light is `500 nm. ` The astronaut will be able to resolve linear object of the size of about .

Options

A. `0.5 m`
B. `5 m`
C. `50m`
D. `500 m`

Answer

C

Explanation

Let `x` be the size of linear object that can be resolved
`:.` Limit of resolution `theta = (x)/(D) = (lambda)/(a)`
`x = (lambda)/(a) xx D = (5 xx 10^(-7) xx 50 xx 10^(5))/(5 xx 10^(-3))`
`x = 50 metre`