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

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

In an expression $a \times 10^{b}$:

What is the $SI$ unit of density?

The unit of angular acceleration in the $SI$ system is

$A$ physical quantity is measured and its value is found to be $nu$, where $n$ is the numerical value and $u$ is the unit. Then which of the following relations is true?