A telescope has an objective lens of `10cm` diameter and is situated at a distance of one kilometre from two objects. The minimum distance between these two objects, which can be resolved by the telescope, when the mean wavelength of light is `5000 Å`, of the order of

Options

A. 0.5 m
B. 5 m
C. 5 mm
D. 5 cm

Answer

C

Explanation

For telescope,
`Delta theta = (1.22 lambda)/(a)`
`a rarr ` diameter of a objective
`rArr (x)/(d) = (1.22 lambda)/(a) `
`rArr x = (1.22 xx 5000 xx 10^(-10) xx 10^(3))/(10 xx 10^(-2)) ` = 6.1 mn
Order will be 5 min.