Question

Give an example of a quantity which is dimensionless?

Answer 1

Dimension

1. Each derived quantity requires proper power for fundamental quantities to represent it.
2. The powers of fundamental quantities, through which they are to be raised to represent a unit-derived quantity, are called dimensions.

Dimensionless quantity

1. Dimensionless quantity is a quantity that has no physical dimensions.
2. Dimensionless quantities are distinct from quantities that have associated dimensions, such as time.

Example of dimensionless quantity

1. Angle, $angle=\frac{arc}{radius}=\frac{\left[L\right]}{\left[L\right]}=\left[M^0{L}^0{T}^0\right]$