What does it mean when the height of a barometer is rising?

$A$ barometer tube reads $76 \ cm$ of mercury. If the tube is gradually inclined at an angle of $60^\circ$ with the vertical,keeping the open end immersed in the mercury reservoir,the length of the mercury column will be ........ $cm$.

Why are two holes made to empty an oil tin?

Who devised for the first time,a method for measuring atmospheric pressure?

On what factors does the pressure at any place depend? Explain.

The figure shows two containers $P$ and $Q$ with the same base area $A$,each filled to the same height with the same liquid. Select the correct alternative.