Question

A beaker containing a liquid, is kept inside a big closed chamber. If the air inside the chamber is continuously pumped out, then the pressure in the liquid near the bottom of the beaker will -

• A. Increase
• B. Decrease
• C. Remain constant
• D. First increase and then decrease.

Answer 1

The correct option is B Decrease

When the air inside the chamber is pumped out the pressure inside the chamber decreases, as the number of molecules colliding with the walls of the chamber reduces.
Let the pressure inside the chamber be '$p$'.


From the figure, we know that the pressure at bottom point A will be given by
$p_A=p+\rho gh----\left(1\right)$
where $\rho$ is the density of the liquid inside the beaker.
As the air inside the chamber is continuously pumped out, the air pressure $p$ decreases.
Hence, from (1), we can conclude that pressure at point A will also decrease.