Question

What are dimensionless quantities? Give few examples.

Answer 1

In dimensional analysis, a dimensionless quantity is a quantity without any physical units and thus a pure number. Such a number is typically defined as a product or ratio of quantities which do have units, in such a way that all the units cancel out.

for example, the ratio of marks of jyoti and pari = 15marks/10 marks=3/2=3:2,

percentage 35%, etc.

Answer 2

Explanation:

Dimensionless variables are the quantities which doesn’t have any dimensions the the value is a variable.

Eg: angle = arc/ radius

Dimensions = L/L

= 1

So angle does not have any dimensions and the value can vary

Dimensionless constant are the quantities which doesn’t have any dimension but the value is a constant

Eg: value of pi = 3.14 or 22/7