The resolving power of a telescope depends on

The resolving power of a telescope whose lens has a diameter of $1.22 \ m$ for a wavelength of $5000 \ \mathring{A}$ is

$A$ telescope of aperture $3 \times 10^{-2} \, m$ diameter is focused on a window at $80 \, m$ distance fitted with a wire mesh of spacing $2 \times 10^{-3} \, m$. Given: $\lambda = 5.5 \times 10^{-7} \, m$,which of the following is true for observing the mesh through the telescope?

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 $mm$)

Two vertical poles are at a distance of $6.28 \, m$ from each other. What should be the maximum distance of an observer from the poles to see them separately? (in $km$)

Two point white dots are $1 \ mm$ apart on a black paper. They are viewed by an eye with a pupil diameter of $3 \ mm$. Approximately,what is the maximum distance at which the dots can be resolved by the eye? (Take wavelength of light $= 500 \ nm$)