The limit of resolution of an oil immersion objective microscope of numerical aperture $0.8$ for light of wavelength $0.6 \mu m$ is

Two points separated by a distance of $0.1 \ mm$ can just be seen in a microscope when light of wavelength $6000 \ Å$ is used. If the light of wavelength $4800 \ Å$ is used,the limit of resolution will become: (in $mm$)

The resolving power of a telescope depends on

We use a simple microscope to magnify an object. The microscope has a numerical aperture of $\sin \alpha = 0.24$. The object is so small that the resolving power of the microscope is fully utilized. If the diameter of the eye's pupil is $d = 4.0 \ mm$ and the least distance of distinct vision is $D = 25 \ cm$,what is the minimum magnifying power of the microscope?

$A$ telescope with objective diameter $R$ is used to observe a distant star emitting light of wavelength $500 \text{ nm}$, at a resolution of $5 \times 10^{-7} \text{ radian}$. The value of $R$ is . . . . . . $\text{cm}$.

Assume that light of wavelength $6000\,\mathring{A}$ is coming from a star. What is the limit of resolution of a telescope whose objective has a diameter of $100\,\text{inch}$?