$1\,g\,cm^{-3} = ....\,kg\,m^{-3}$

Describe the range of lengths and the relationships between various units of length.

$1\,J =$ ............ $\text{calorie}$. (Fill in the blank)

$1 \, g = \dots \, a.m.u.$

The $SI$ unit of length is 'metre'. Suppose we adopt a new unit of length which equals $x$ metre. Then,the area of $1 \ m^2$ expressed in terms of the new unit has a magnitude of:

If ${u_1}$ and ${u_2}$ are the units selected in two systems of measurement and ${n_1}$ and ${n_2}$ are their respective numerical values,then: