Assume that light of wavelength 6000 Å is coming from a star. What is the limit of resolution of a telescope whose objective has a diameter of 100 inch ?

Explanation

A 100 inch telescope implies that `2a = 100 "inch" = 254 cm.` Thus if,
`lambda~~6000Å=6xx10^(-5)cm`
then
`Delta theta~~(0.61xx6xx10^(-5))/(127)~~2.9xx10^(-7)" radians"`