$1 \mathring{A} = \dots \dots \text{ fm}$

The total plane angle subtended by a circle at its centre is ......... $rad$.

The value of acceleration due to gravity is $9.8 \, m s^{-2}$. Its value in $ft/s^2$ is approximately:

Explain this statement clearly: "To call a dimensional quantity 'large' or 'small' is meaningless without specifying a standard for comparison". In view of this,reframe the following statements wherever necessary:
$(a)$ atoms are very small objects
$(b)$ a jet plane moves with great speed
$(c)$ the mass of Jupiter is very large
$(d)$ the air inside this room contains a large number of molecules
$(e)$ a proton is much more massive than an electron
$(f)$ the speed of sound is much smaller than the speed of light.

$A$ micron is related to a centimetre as:

Which of the following is the largest: Astronomical Unit,Light Year,or Parsec?