Concepts Of Physics MCQ Edition [Volume 1]PhysicsFluid Mechanics
A beaker containing a liquid is placed inside a large closed jar. If the air within the jar is continuously pumped out, the pressure in the liquid near the bottom will
Options
- Afirst decrease and then increase
- Bremain constant
- Cincrease
- Ddecrease
Correct answer
D. decrease
Step-by-step solution
The pressure at a depth h near the bottom of the liquid is given by: P = P₀ + g h where P₀ is the pressure of the air inside the closed jar, is the density of the liquid, and g is the acceleration due to gravity. As the air within the jar is continuously pumped out, the pressure of the air P₀ above the liquid surface decreases. Since P₀ decreases and the term g h remains constant (assuming the height of the liquid does not change significantly), the total pressure P near the bottom of the liquid will decrease.