Assume that light of wavelength $400 \mathrm{~nm}$ is coming from a distant star. The limit of resol

Question

Assume that light of wavelength $400 \mathrm{~nm}$ is coming from a distant star. The limit of resolution of a telescope whose objective lens has a diameter of $1.22 \mathrm{~m}$ is exactly

Professor PC Thomas Classes · Answer

(a) : The limit of resolution of a telescope (minimum resolvable angular separation) is given by Rayleigh's criterion: $\Delta 	heta = \frac{1.22\lambda}{D}$. Given the wavelength $\lambda = 400 	imes 10^{-9} \mathrm{~m}$ and the diameter $D = 1.22 \mathrm{~m}$. Substituting the values: $\Delta 	heta = \frac{1.22 	imes 400 	imes 10^{-9}}{1.22} = 400 	imes 10^{-9} \mathrm{~rad} = 4.0 	imes 10^{-7} \mathrm{~rad}$.