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

Answer

C

Explanation

`alpha_(min)=(1.22lambda)/(D)=(d_m)/(R)`
`thereforeR=(Dxxd_m)/(1.22lambda)`
`thereforeR=(3xx10^(-3)xx1xx10^(-3))/(1.22xx500xx10^(-9))`
`thereforeR=4.918` m
`therefore` R=5 m