Question

Define the dimension of a physical quantity.

Answer 1

Dimension:

1. Dimensions are the powers of any physical quantity that are raised on fundamental units to express its unit.
2. The dimensional formula is the expression that shows how and which of the base quantities represent the dimensions of a physical quantity.
3. The dimension of a physical quantity is the number of occurrences of the fundamental units of mass, length, and time in the physical quantity.
4. For example, $F=\left[ML{T}^{-2}\right]$ is the dimension force. It is due to the fact that the unit of Force is N(newton) or $\frac{\text{kg}\times \text{m}}{{\text{s}}^2}$.
   $$\begin{gathered} mass\left(M\right)=kg \\ meter\left(L\right)=m \\ seconds\left(T\right)=s \end{gathered}$$
   
5. Hence, $F=\frac{kgxm}{s^2}=\left[ML{T}^{-2}\right]$