Give the names of physical quantities which are needed to describe a fluid.

Which of the following quantities is expressed as force per unit area?

Consider two liquids $A$ and $B$ in a $U$-shaped tube in static equilibrium as shown in the figure. If the density of the liquid $A$ is twice the density of liquid $B$,then the relation between $h_A$ and $h_B$ is

Two liquids of densities $\rho_{1}$ and $\rho_{2}$ (where $\rho_{2} = 2\rho_{1}$) are filled behind a vertical wall of height $10 \; m$ and width $w$,as shown in the figure. Each liquid has a height of $h = 5 \; m$. The ratio of the force exerted by the upper liquid on the part $MN$ to the force exerted by the lower liquid on the part $NO$ is (Assume that the liquids do not mix):

The pressure at the sea surface is .......... $P_{a}$.

$A$ thin uniform tube is bent into a circle of radius $r$ in the vertical plane. Equal volumes of two immiscible liquids,whose densities are ${\rho _1}$ and ${\rho _2}$ $({\rho _1} > {\rho _2})$,fill half the circle. The angle $\theta$ between the radius vector passing through the common interface and the vertical is