Calculate the aperture of the objective of a telescope which may be used to just resolve two stars separated by `6.1 times 10^-6` radian, if light from the star has a wavelength of 550 nm.

Explanation

Limit of resolution, `Delta theta=6.1 times 10^-6 ` radian
Wavelength, `lamda=550 nm=5.5 times 10^-7 m`
`Deltatheta=(1.22 lamda)/a=(1.22 times5.5 times10^-7)/(6.1 times10^-6)=0.11m`