Assuming human pupil to have a radius of 0.25 cm and a comfortable viewing distance of 25 cm, the minimum separation between two objects than human eye can resolve at 500nm wavelength is :

Options

A. `1 mu m`
B. `30 mu m`
C. `100 mu m`
D. `300 mu m`

Answer

B

Explanation

`sin theta = (0.25)/(25) = (1)/(100)`
Resolving power of eye is
`RP = (1.22 lambda)/(2 mu sin theta) = (1.22 xx (500 xx 10^(-9)))/(2 xx 1 xx (1//100))`
`= 3.05 xx 10^(-5)m ~~ 30 mu m`