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

Two luminous point sources separated by a certain distance are at $10 \,km$ from an observer. If the aperture of his eye is $2.5 \times 10^{-3} \,m$ and the wavelength of light used is $500 \,nm$, the distance of separation between the point sources just seen to be resolved is (in $\,m$)

Resolving power of a telescope can be increased by increasing

Large apertures of telescopes are used for

The distance of the moon from earth is $3.8 \times 10^5 \text{ km}$. The eye is most sensitive to light of wavelength $5500 \text{ Å}$. The separation of two points on the moon that can be resolved by a $500 \text{ cm}$ telescope will be......$m$.

$A$ monochromatic light of wavelength $6000 \text{ \AA}$ coming from a star is detected in a $100 \text{ inch}$ telescope. The limit of resolution of the telescope is approximately