If dimensions of critical velocity $$\upsilon $$_c of a liquid flowing through a tube are expressed as $$\left[ {{\eta ^x}{\rho ^y}{r^z}} \right]$$ where $$\eta ,\rho $$ and r are the coefficient of viscosity of liquid, density of liquid and radius of the tube respectively, then the values of x, y and z are given by

If energy (E), velocity (V) and time (T) are chosen as the fundamental quantities, the dimensional formula of surface tension will be

If force (F), velocity (V) and time (T) are taken as fundamental units, then dimensions of mass are

The pair of quantities having same dimensions is