Physics · Geography

Atmospheric Physics and Humidity

878 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

In the case of saturated air, the column of air tends to be in stable equilibrium, when the prevailing lapse rate

  1. is equal to the wet adiabatic lapse rate

  2. is more than the wet adiabatic lapse rate

  3. is less than the wet adiabatic lapse rate

  4. does not vary with the wet adiabatic lapse rate
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In a saturated air mass, if the prevailing lapse rate is less than its wet adiabatic lapse rate, the atmosphere is said to be in stable equilibrium. 

Multiple choice

The boiling point of water

  1. Depends on atmospheric pressure

  2. Is always 1000 C

  3. Depends on the material of the container

  4. Depends on relative humidity
Reveal answer Fill a bubble to check yourself
B Correct answer
Multiple choice

At mean sea level, a difference of one hPa of pressure corresponds to approximately how much change in altitude?

  1. 30 feet

  2. 50 feet

  3. 70 feet

  4. 100 feet
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

At mean sea level, 1 hPa of pressure change corresponds to approximately 27-30 feet of altitude change (commonly rounded to 30 feet). This is because pressure decreases with altitude at a roughly constant rate in the lower atmosphere. The other options (50, 70, 100 feet) are too large for a single hPa difference.

Multiple choice

One inch of mercury corresponds to how much difference in altitude?

  1. 1000 feet

  2. 1500 feet

  3. 30 feet

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

One inch of mercury (inHg) is a larger pressure unit than hPa. 1 inHg ≈ 33.86 hPa. Since 1 hPa ≈ 30 feet, 1 inHg ≈ 33.86 × 30 ≈ 1016 feet (commonly rounded to 1000 feet). This is a standard conversion used in aviation - 1000 feet per inch of mercury is the practical approximation. 30 feet is far too small (that's for 1 hPa).

Multiple choice

Jet aircrafts fly very easily and smoothly in the lower stratosphere. What could be the appropriate explanation?

  1. There are no clouds or water vapours in the lower stratosphere.
  2. There are no vertical winds in the lower stratosphere.

Which of the statements given above is/are correct in this context?

  1. 1 only

  2. 2 only

  3. Both 1 and 2

  4. Neither 1 nor 2
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Jets fly in the lower stratoshpere to avoid turbulence. There are no clouds and the air is dry with little water vapours.

Multiple choice

If there is no sun, the colour of the sky would be

  1. blue

  2. black

  3. red

  4. grey
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The blue color of the sky is caused by Rayleigh scattering of sunlight by atmospheric particles. Without the sun, there would be no light source to scatter, making the sky appear black (dark) as in space. The other colors mentioned require sunlight to be visible.

Multiple choice

The process of __________ of water helps in the formation of water vapours in the atmosphere.

  1. condensation

  2. evaporation

  3. distillation

  4. fragmentation
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Evaporation is the process by which water changes from liquid to gas (water vapour). This occurs when water molecules gain enough energy from heat to escape into the atmosphere. Condensation is the opposite process (gas to liquid), while distillation is a separation technique and fragmentation is breaking apart solids.

Multiple choice

Which of the following statements is / are correct regarding water vapour? (a) Water vapour is the water that diffuses in the air above its boiling point. (b) Water vapour is water in its liquid state. (c) Fog and mist are forms of water vapour. (d) It is invisible.

  1. Only a

  2. Only b

  3. Only d

  4. Both a and c

  5. Both b and c
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Yes, it is the only correct statement. Water vapour is water in its gaseous state. Cloud, fog, or mist are all liquid water, not water vapour.

Multiple choice

The rate of fall of pressure ____ in warm air than in cold air.

  1. increases

  2. decreases

  3. is same

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

Pressure falls more rapidly with altitude in cold, dense air than in warm, less dense air. This is because cold air is denser and has a shorter scale height - the pressure decreases more quickly per unit of altitude gain compared to warm air.

Multiple choice

___ is the pressure when aerodrome pressure is reduced to MSL under ISA condition.

  1. QFE

  2. QNH

  3. QNE

  4. QFF
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

QNH is the pressure setting that reduces aerodrome pressure to mean sea level (MSL) under International Standard Atmosphere (ISA) conditions. QFE is the actual pressure at the aerodrome elevation, QNE is the pressure at the transition altitude, and QFF is MSL pressure using actual (not ISA) temperature conditions.