An air bubble of radius $r$ in water is at depth $h$ below the water surface at same instant. If $P$ is atmospheric pressure and $d$ and $T$ are the density and surface tension of water respectively. The pressure inside the bubble will be
$P + hdg -(4\pi/r)$
$P + hdg + (2\pi/r)$
$P + hdg -(2\pi/r)$
$P + hdg + (4\pi/r)$
A soap bubble is blown with the help of a mechanical pump at the mouth of a tube. The pump produces a certain increase per minute in the volume of the bubble, irrespective of its internal pressure. The graph between the pressure inside the soap bubble and time $t$ will be-
A liquid column of height $0.04 \mathrm{~cm}$ balances excess pressure of soap bubble of certain radius. If density of liquid is $8 \times 10^3 \mathrm{~kg} \mathrm{~m}^{-3}$ and surface tension of soap solution is $0.28 \mathrm{Nm}^{-1}$, then diameter of the soap bubble is . . . . . . .. . $\mathrm{cm}$.
$\text { (if } g=10 \mathrm{~ms}^{-2} \text { ) }$
There are two liquid drops of different radii. The excess pressure inside over the outside is
Consider the following two statement $A$ 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.
A spherical drop of water has radius $1\, mm$ If surface tension of water is $70 \times {10^{ - 3}}\,N/m$ difference of pressures between inside and out side of the spherical drop is ........ $N/{m^{ - 2}}$