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 points separated by $0.05 \, mm$ can just be inspected in a microscope when light of wavelength $6000 \, \mathring{A}$ is used. If light of wavelength $3000 \, \mathring{A}$ is used,then the limit of resolution becomes ........... $mm$.

The diameter of the objective lens of a telescope is $250\, cm$. For light of wavelength $600\, nm$ coming from a distant object, the limit of resolution of the telescope is close to:

To increase both the resolving power and magnifying power of a telescope:

The human eye has an approximate angular resolution of $\theta = 5.8 \times 10^{-4} \text{ rad}$ and a typical photo printer prints a minimum of $300 \text{ dpi}$ (dots per inch, $1 \text{ inch} = 2.54 \text{ cm}$). At what minimal distance $d$ should a printed page be held so that one does not see the individual dots (in $\text{ cm}$)?

If the numerical aperture $(NA)$ of a microscope is increased,then its: