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. `50 m`
D. `500km`

Answer

C

Explanation

`theta = (1.22lambda)/(d) = (1.22xx500xx10^(-9))/(5xx10^(-3)) = 1.22xx10^(-4)rad`
`theta = (x)/(d) rArr 1.22 xx 10^(-4) = (x)/(400xx10^(3))`
`x = 50 m`