A man wants to distinguish between two pillars located at a distance of `11 km`. What should be the minimum distance between the pillars ?

Answer

C

Explanation

As the limit of resolution of human eye is
`theta = 1' = (1^@)/(60) = (pi)/(60 xx 180) radian`
If `x` is minimum distance between the pillars, and
`d = 11 km = 11 xx 3^3 m`, then from `theta = (x)/(d)`
`x = d xx theta = 11 xx 10^3 xx (pi)/(60 xx 180) m = 3.2 m`
The correct intergral answer is `x = 3 m`.