PHYSICAL QUANTITY

 A quantity which can be measured and expressed in form of laws is called a physical quantity.Physical quantity (PQ)=Magnitude×Unit=n×u where,n represents the numerical value and u represents the unit.as the unit(u) changes, the magnitude(n) will also change but product ' nu ' will remain same.

i.e.  n u = constant, or 

n1u1 = n2u2 = constant