The resolving limit of a healthy human eye is about:

The numerical aperture of a microscope is $0.12$, and the wavelength of light used is $600 \, nm$. Then its limit of resolution will be nearly $............. \, \mu m$.

The limit of resolution of a telescope is $3.0 \times 10^{-7} \text{ rad}$. Assuming that it is used to see the light of wavelength $525 \text{ nm}$ from a star, what should be the diameter of the objective (in $\text{ m}$)?

Two stars are $10$ light years away from the Earth. They are seen through a telescope of objective diameter $30\, cm$. The wavelength of light is $600\, nm$. To see the stars just resolved by the telescope,the minimum distance between them should be ( $1$ light year $= 9.46 \times 10^{15}\, m$) of the order of

If a microscope is placed in air,the minimum separation of two objects seen as distinct is $6 \mu m$. If the same is placed in a medium of refractive index $1.5$,then the minimum separation of the two objects to be seen as distinct is: (in $\mu m$)

An electron microscope is superior to an optical microscope in