A barometer kept in an elevator reads $76 \,cm$ when the elevator is accelerating upwards. The most likely pressure inside the elevator (in $cm$ of $Hg$ ) is ........

An open glass tube is immersed in mercury in such a way that a length of $8\ cm$ extends above the mercury level. The open end of the tube is then closed and sealed and the tube is raised vertically up by additional $46\ cm$. What will be length of the air column above mercury in the tube now ....... $cm$ ?

( Atmospheric pressure = $76\ cm$ of $Hg$)

Two copper vessels $A$ and $B$ have the same base area but of different shapes. $A$ takes twice the volume of water as that $B$ requires to fill upto a particular common height. Then the correct statement among the following is

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

The limbs of a $U$ -tube glass are lowered into vessels $A$ and $B, A$ containing water. Some air is pumped out through the top of the tube $C$. The liquids in the left hand limb $A$ and the right hand limb $B$ rise to heights of $10\, cm$ and $12\, cm$ respectively. The density of liquid $B$ is ........ $g/cm^3$

Figure here shows the vertical cross section of a vessel filled with a liquid of density $\rho$. The normal thrust per unit area on the walls of the vessel at the point $P$, as shown, will be