$A$ drop of liquid of density $\rho$ is floating half-immersed in a liquid of density $d$. If $T$ is the surface tension,then the diameter of the drop is:

Consider the following two statements $A$ and $B$,and identify the correct choice in the given answers.
$A :$ The excess pressure inside a small liquid drop is more than that of a big drop.
$B :$ As the aeroplane moves fast on the runway,the pressure is more on the upper surface of its wings and less on the bottom surface of the wings.

The radius of an air bubble at the bottom of a lake is $r$,and it becomes $2r$ when the air bubble rises to the top surface of the lake. If $P \text{ cm}$ of water is the atmospheric pressure,then the depth of the lake is: (in $P$)

Two cylindrical vessels of equal cross-sectional area of $2 \ m^2$ contain water up to heights of $10 \ m$ and $6 \ m$,respectively. If the vessels are connected at their bottom,then the work done by the force of gravity is (Density of water is $10^3 \ kg/m^3$ and $g = 10 \ m/s^2$):

In a water voltameter,the electrolysis of ...... takes place.

$A$ glass tube of uniform cross-section is filled with water and mounted on a rotatable shaft as shown in the figure. If the tube is rotated with a constant angular velocity $\omega$,then: