Qstnid -Ii-8-suppose The Pressure At The Surface Of Mercury In A Barometer Tube Is P<sub>1</sub> And The Pressure At The Surface Of Mercury In The Cup Is P<sub>2</sub>. - 13: Fluid Mechanics - Neet-xii-physics

Home Learn Fast select Course

Show Unit/Chapter Change Unit Change Subject Last Menu

NEET-XII-Physics

13: Fluid Mechanics

with Solutions - page 2

Qstn# ii-8 Prvs-Qstn Next-Qstn

#8
Suppose the pressure at the surface of mercury in a barometer tube is P₁ and the pressure at the surface of mercury in the cup is P₂.
(a) P₁ = 0, P₂ = atmospheric pressure
(b) P₁ = atmospheric pressure P₂ = 0
(c) P₁ = P₂ = atmospheric pressure
(d) P₁ = P₂ = 0
digAnsr: a
Ans : (a) P₁ = 0, P₂ = atmospheric pressure
The upper part of the tube contains vacuum as the mercury goes down and no air is allowed in. Thus, the pressure at the upper end, i.e., at the surface of mercury in a barometer tube is zero (P₁= 0). However, the pressure at the surface of mercury in the cup or any another point at the same horizontal plane is equal to the atmospheric pressure.
Page No 271: