Which of the following sets cannot enter into the list of fundamental quantities in any system of units?

It is desirable that the standards of units be easily available, invariable, indestructible and easily reproducible. If we use foot of a person as a standard unit of length, which of the above features are present and which are not?

Suggest a way to measure:

A. the thickness of a sheet of paper,

B. the distance between the sun and the moon.

A physical quantity is measured and the result is expressed as nu where u is the unit used and n is the numerical value. If the result is expressed in various units then

Suppose a quantity x can be dimensionally represented in terms of M, L and T, that is, [x] = M^a L^b T^c . The quantity mass