# Unit and dimension

• Could you simplify the question please?

• @Indranil
If a quantity is unitless then it means that either the quantity is a ratio or a constant. So it does not have any dimensions i.e no specific measurements.
So a unitless quantity can never have non zero dimensions.

• @Indranil
If a quantity is unitless then it means that either the quantity is a ratio or a constant. So it does not have any dimensions i.e no specific measurements.
So a unitless quantity can never have non zero dimensions.
'Non zero dimension' means what?

• @Indranil it is unitless. No units. Constant

• @Indranil
Dimension is a measure of any physical quantity. For example when you say that the size of a blackboard is, let’s say 90cm x 30cm, then here length and breadth are the dimensions of the blackboard.
Similarly when you say that speed is 36 km/hr then length(distance) and time are the dimensions here.
So zero dimension refers that there is no physical measure to evaluate the given quantity.