Two point white dots are 1 mm apart on a black paper. They are viewed by eye of pupil diameter 3 mm. Approximately, what is the maximum distance at which these dots can be resolved by the eye ? [Take wavelength of light = 500 nm]

Options

A. 5m
B. 1m
C. 6m
D. 3m

Answer

A

Explanation

Let dots can be resolved by eye at maximum distance R then `(1.22 lambda)/(D) = (d)/(R)`
`implies R = (Dd)/(1.22 lambda) = ((3xx 10^(-3))(1 xx 10^(-3)))/(1.22 xx 500 xx 10^(-9))`
= 4. 92 m = 5 m