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

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 $\text{ cm}$)?

$A$ telescope has an objective lens of $10\, cm$ diameter and is situated at a distance of $1\, km$ from two objects. The minimum distance between these two objects which can be resolved by the telescope,when the mean wavelength of light is $5000\,\mathring{A}$,is the order of

The diameter of the objective of a telescope is $1 \ m$. Its resolving limit for light of wavelength $4538 \ \text{Å}$ will be:

If an object kept at the least distance of distinct vision is just resolved with light of wavelength $500 \ nm$ and a pupil of diameter $1 \ mm$,at what distance will the object be just resolved if the wavelength is $400 \ nm$ and the pupil diameter is $0.8 \ mm$ (in $cm$)?

Assuming the human pupil to have a radius of $0.25 \ cm$ and a comfortable viewing distance of $25 \ cm$,the minimum separation between two objects that the human eye can resolve at $500 \ nm$ wavelength is nearly: (in $\mu m$)