What is heat? Write $SI$ and $CGS$ unit of heat and give their relation.

The latent heat of $1 \, g$ of steam is $536 \, cal/g$. Its value in $J/kg$ is:

Why do we have different units for the same physical quantity?

What is a system of units? Write the different types of systems of units.

Which of the following systems of units is not based on units of mass,length,and time alone?

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.