The work done in splitting a drop of water of $1\, mm$ radius into $10^6$ droplets is (surface tension of water $72\times10^{-3}\, N/m$) :

In making an alloy, a substance of specific gravity $s_1$ and mass $m_1$ is mixed with another substance of specific gravity $s_2$ and mass $m_2$ then the specific gravity of the alloy is

A ………. $m/s$ speed the velocity head of water is equal to pressure head of $40\, cm$ of $Hg$ .

A spherical body of mass $m$ and radius $r$ is allowed to fall in a medium of viscosity $\eta $. The time in which the velocity of the body increases from zero to $0.63\, times$ the terminal velocity $(v)$ is called time constant $\left( \tau  \right)$. Dimensionally $\tau $ can be represented by

The terminal velocity of a small sized spherical body of radius $r$ falling vertically in a viscous liquid is given by the proportionality