Question

A beaker containing a liquid is kept inside a big closed jar. If the air inside the jar is continuously pumped out, the pressure in the liquid near the bottom of the liquid will
(a) increase
(b) decrease
(c) remain constant
(d) first decrease and then increase

Answer 1

Answer:

remains constant. because liquid contains air

Answer 2

(b) Decrease

Explanation:

• The pressure in the liquid near the bottom of the liquid  
• P = P0 +  ρhg
• [Where P0 = Atmospheric pressure; ρ = density of liquid; g = gravitational field strength]
• As per the given problem, the air inside the jar is continuously pumped out which means that the density of air is decreased inside the jar. Since the pressure is directly proportional to density (P ∝ ρ), the atmospheric pressure (P0) also decreased.  
• So the pressure in the liquid near the bottom of the liquid will also be decreased.