Two poles are separated by a distance of $3.14 \, m$. The resolving power of the human eye is $1 \, min$ of an arc. The maximum distance from which one can identify the two poles distinctly is

Wavelengths of light used in an optical instrument are $\lambda_1 = 4000 \; \mathring{A}$ and $\lambda_2 = 5000 \; \mathring{A}$. The ratio of their respective resolving powers (corresponding to $\lambda_1$ and $\lambda_2$) is:

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 $\text{ cm}$)?

The resolving power of a compound microscope will be maximum when

The resolving power of the human eye is $1'$. At what distance $r$ (in $km$) can two objects separated by a distance of $d = 3 \, m$ be seen as distinct?

The angular resolution of a $10 \;cm$ diameter telescope at a wavelength of $5000 \;\mathring A$ is of the order of: