Physics · Geography

Atmospheric Physics and Humidity

935 Questions

Study the principles of atmospheric physics and humidity through these practice questions. Key subjects include the rate of evaporation, temperature inversions, and relative humidity measurements. These concepts are vital for geography and physics exams.

Evaporation and condensationRelative humidity conceptsAtmospheric pressure effectsTemperature inversion

Atmospheric Physics and Humidity Questions

Multiple choice physics the kinetic model of matter evaporation heat, internal energy and work phase change

Which of the following does not affect the rate of evaporation?

  1. Pressure on evaporating substance

  2. Exposed surface area of the evaporating substance

  3. Shape of the evaporating substance

  4. Temperature
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Evaporation is a process in which some molecules of a liquid, which have greater kinetic energy, escape from the liquid and enter the atmosphere.

If pressure is greater, the molecules need greater energy to overcome the pressure and hence evaporation decreases with increase in pressure.
Due to more surface area, more molecules get a chance to escape, hence faster is the evaporation.
At higher temperature, molecules have greater kinetic energy, hence can easily escape the liquid.
But shape of the surface of the liquid doesn't affect evaporation.

Multiple choice physics the kinetic model of matter evaporation heat, internal energy and work phase change

Why skin feels dry in an air-conditioned room?

  1. Because the rate of evaporation decreases with lower humidity.

  2. Because the rate of evaporation increases with lower humidity.

  3. Because the rate of evaporation remains same with lower humidity.

  4. Because the rate of evaporation increases with higher humidity.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Evaporation is a process in which some molecules of a liquid, which have greater kinetic energy, escape from the liquid and enter the atmosphere.

When the humidity is lower, the air's capacity to absorb vapour is greater. The adhesive force of attraction between liquid molecules increases and more molecules escape into the atmosphere. Hence evaporation is greater in dry air.

Multiple choice physics the kinetic model of matter evaporation heat, internal energy and work phase change

Water evaporates under atmospheric pressure. Without changing the temperature, the same water is placed in a partial vacuum. The rate of evaporation will

  1. increase

  2. drop to zero

  3. decrease

  4. remain unaffected
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
In partial vacuum, the pressure is very less.
According to Le-chatelier's principle on decreasing pressure, volume increases so more water converts into gas (vapour).
Multiple choice physics the kinetic model of matter evaporation heat, internal energy and work phase change

A fan produces a feeling of comfort because:

  1. A fan supplies cool air

  2. Of the evaporation of sweat

  3. Fan increase the humidity in air

  4. Fan decrease the humidity in air
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A fan produces a feeling of comfort because of evaporation of sweat because on hot day, our body sweats to loose heat through the evaporation of moisture.In still air evaporation is slow. A fan or breeze helps by replacing hot humid air with cooler dries air that allow for more evaporation


Multiple choice physics the kinetic model of matter evaporation heat, internal energy and work phase change

Relative humidity is the percentage of the

  1. absolute humidity value to the amount of humidity actually present

  2. increase of humidity/absolute humidity

  3. amount of humidity actually present to the absolute humidity

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The ratio of actual amount of water vapour present in volume of air at a given temperature to maximum amount that air could hold at that temperature, expressed as percentage is relative humidity.

Multiple choice physics the kinetic model of matter evaporation heat, internal energy and work phase change

When we dry our wet clothes in sun in a line then which phenomena applies to make them dry?

  1. Sublimation

  2. Fermentation

  3. Vaporisation

  4. Evaporation
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Clothes are dried by evaporation due to heat from sunlight . In a line , clothes get sunlight for whole day , and due to heat from sun, rate of evaporation increases and clothes dry quickly .

Multiple choice physics pressure in liquids and gases pressure dependence on force and area concept of pressure pressure on surface

We sit in the room with windows open. Then

  1. Air pressure on the floor of the room equals the atmospheric pressure but the air pressure on the ceiling is negligible

  2. Air pressure is nearly the same on the floor, the walls and ceiling

  3. Air pressure on the floor equals the weight of the air column inside the room (from floor to ceiling) per unit area

  4. Air pressure on the walls is zero since the weight of air acts downward
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Answer is B.

Varying air pressures in buildings result from uncontrolled air flow patterns.When a space is under a positive air pressure, indoor air will be pushed outward in the walls, floor and ceiling. When a space is under a negative pressure, air will be pulled inward through the walls, floor and ceiling. 
In this case, the windows in the room are open and so there is free flow of air in and out of the room. 
Hence, air pressure is nearly the same on the floor, the walls and ceiling.

Multiple choice physics pressure in liquids and gases pressure dependence on force and area concept of pressure pressure on surface

Air is pumped into an automobile tube upto a pressure of $200 \mathrm{kP}  $ in the morning when the air temperature is $  22^{\circ} \mathrm{C}  $ . During the day, temperature rises to $ 42^{\circ} \mathrm{C}  $ and the tube expands by $2 \%  $ . The pressure of the air in the tube at this temperature, will be approximately

  1. $212 \mathrm{kPa} $
  2. $209 k P a $
  3. $206 \mathrm{kPa} $
  4. $200 \mathrm{kPa} $
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$\begin{array}{l} Given\, \, { P _{ 1 } }=200\, \, k\, pa \ { T _{ 1 } }=22^{ \circ  }C=273+22-295K \ { T _{ 2 } }=42^{ \circ  }C=273+42=315K \ PV=nRT \ \left( { \dfrac { { PV } }{ T }  } \right) ={ { constant } }\left[ \begin{array}{l} { { Since } }\, \, number\, \, of\, \, moles \ and\, \, R\, \, are\, \, { { constant } } \end{array} \right]  \ \dfrac { { { P _{ 1 } }{ V _{ 1 } } } }{ { { T _{ 1 } } } } =\dfrac { { { P _{ 2 } }{ V _{ 2 } } } }{ { { T _{ 2 } } } }  \ \dfrac { { 200\times 1 } }{ { 295 } } =\dfrac { { { P _{ 2 } }\left( { 1.02 } \right)  } }{ { 315 } }  \ { P _{ 2 } }=\dfrac { { 200\times 315 } }{ { 295\times 1.02 } } \, \, kPa \ = 209\, \, kPa \end{array}$

Option B.

Multiple choice biology transport in plant transport of water and minerals conduction of water and minerals absorption of water and minerals in plants

In poorly aerated soil, the rate of water absorption will

  1. Increase

  2. Decrease

  3. Remains the same

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Poorly aerated soil, particularly when it is deficient in oxygen, retards absorption of water from the soil. Accumulation of $CO _2$ in the soil also inhibits absorption.

Multiple choice botany water absorption and ascent of sap in plants factors affecting the transport of water and minerals in plants ascent of sap long distance transport of water

A sufficient atmospheric pressure required to push the water upto the top of tall plants must be

  1. 2 atm

  2. 6 atm

  3. 20 atm

  4. All of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Taller plants like Eucalyptus need higher pressure to raise the water up. While the value of root pressure ranges from 2.5 atmospheres. A pressure of about 20 atm. is required to raise the water to tops of tall trees.