A drop of water of volume $0.05\, cm^3$ is pressed between two glass plates, as a consequence of which it spreads and occupies an area of $40\, cm^2$. If the surface tension of water is $70\, dyne/cm$, then the normal force required to separate out the two glass plates will be in Newton
$90$
$44.8$
$22.4$
$448$
In Jager's method, at the time of bursting of the bubble
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 ........ $N/{m^{ - 2}}$
If pressure at half the depth of a lake is equal to $2/3$ pressure at the bottom of the lake then what is the depth of the lake...... $m$
A capillary type tube $AB$ is connected to a manometer $M$ as shown in the figure. Stopper $S$ controls the flow of air. $AB$ is dipped into a soap solution where surface tension is $T$ . On opening the stopper for a while, a bubble is formed at $B$ end of the manometer and the level difference in manometer limbs is $h$ . If $P$ is the density of manometer soap solution and $r$ the radius of curvature of bubble, then the surface tension $T$ of the liquid is given by ...
A small soap bubble of radius $4\,cm$ is trapped inside another bubble of radius $6\,cm$ without any contact. Let $P_2$ be the pressure inside the inner bubble and $P_0$ the pressure outside the outer bubble. Radius of another bubble with pressure difference $P_2 - P_0$ between its inside and outside would be....... $cm$