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

Options

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

Answer

C

Explanation

Resolution limit `=(1.22lambda)/(d)`
Again, resolution limit `=sin theta=theta=(y)/(D)`
Where y = distance between two points and D=maximum distance at which dots can be resolved.
`:.(y)/(D)=(1.22lambda)/(d)`
or `D=(yd)/(1.22lambda)`
or `D=((10^(-3))xx(3xx10^(-3)))/((1.22)xx(5xx10^(-7)))=(30)/(6.1)=5m`