Chapter 3, Problem 3A.5E

(a)

Interpretation Introduction

Interpretation:

Height difference between two sides of $\text{Hg}$ in the manometer has to be determined.

Concept Introduction:

Force exerted by gas on unit area is pressure. It is can be calculated as follows:

  $P=\frac{F}{A}$

Here,

$\text{P}$ is pressure, $\text{F}$ is force and $\text{A}$ is area of an object.

Pressure of an atmosphere can be measured through manometer by the relation as follows:

  $P=dhg$

Here,

$d$ is density

$h$ is height of mercury.

$g$ is acceleration of free fall.

Manometer is a device as barometer employed to measure pressure of gas trapped in container. Weight of $\text{Hg}$ in glass tube is balanced as per weight of air in atmosphere. Weight of $\text{Hg}$ in glass tube increases until it becomes equal to atmospheric pressure which is nothing but weight of air itself above the reservoir. As soon as equilibrium is reached between weight of both $\text{Hg}$ and air, height of mercury in vertical column is taken as measure of pressure.

(b)

Interpretation Introduction

Interpretation:

Whether the side attached to bulb or side open to atmosphere has higher pressure has to be specified.

Concept Introduction:

Refer to part (a).

(c)

Interpretation Introduction

Interpretation:

Height difference between two sides of $\text{Hg}$ in the manometer if a student mistakenly switch the numbers for side of manometer has to be determined.

Concept Introduction:

Refer to part (a).