C07 - Humidity

Question 1

Define Humidity?

Answer 1

The amount of Water Vapour in the Atmosphere.

Question 2

What is the term given when changing Ice to Water and the Latent Heat process (2)?

Answer 2

• Melting.

- Latent Heat Absorbed.

Question 3

What is the term given when changing Water to Gas and the Latent Heat process (2)?

Answer 3

• Evaporation / Vapourisation.

- Latent Heat Absorbed.

Question 4

True or False. For any given Temperature or Pressure, the air can only contain a certain amount of Water Vapour?

Answer 4

True.

Question 5

‘____’ Air can hold a lot more Water Vapour than ‘____’ Air (2)?

Answer 5

• Warm.

- Cold.

Question 6

For any given ‘____’, the air can only contain a certain amount of Water Vapour?

Answer 6

Temperature or Pressure.

Question 7

What is the term given when changing Gas to Water and the Latent Heat process (2)?

Answer 7

• Condensation.

- Latent Heat Released.

Question 8

For Condensation to occur the Air must be ‘____’?

Answer 8

Cooled.

Question 9

When Condensation can be seen with the human eye, what phenomenon can we see (4)?

Answer 9

• Steam.
• Dew.
• Fog.
• Clouds.

Question 10

What is the term given when changing Water to Solid and the Latent Heat process (2)?

Answer 10

• Freezing.

- Latent Heat Released.

Question 11

True or False. Liquid form can still exist below 0°C?

Answer 11

True.

Question 12

What is the term given to a Liquid which is below 0°C?

Answer 12

Supercooled Water Droplets.

Question 13

What is the term given when changing Gas to Solid and Solid to Gas?

Answer 13

Sublimation.

Question 14

True or False. Sublimation can also be seen at high Altitudes when you emerge from icing conditions?

Answer 14

True.

Question 15

How is Humidity measured?

Answer 15

By Hygrometers.

Question 16

Name two types of Hygrometers?

Answer 16

• Digital.

- Psychrometer.

Question 17

What is the name of the two thermometers found in the a Psychrometer?

Answer 17

• Dry Bulb.

- Wet Bulb.

Question 18

Define Absolute Humidity?

Answer 18

A quantity representing the actual amount of Water Vapour in a Gas.

Question 19

What is the measurement for Absolute Humidity?

Answer 19

g/m³.

Question 20

Define Specific Humidity?

Answer 20

The ratio of Water Vapour content to the Total Air Content on the mass basis.

Question 21

The Humidity Mixing Ratio ‘____’ with a decrease in Atmospheric Pressure?

Answer 21

Increases.

Question 22

The Saturated Humidity Mixing Ratio is maximum when the air is ‘____’?

Answer 22

Saturated.

Question 23

‘____’ Temperatures require more Water Vapour to reach saturation?

Answer 23

Higher.

Question 24

Lower Temperatures require ‘____’ Water Vapour to reach saturation?

Answer 24

Less.

Question 25

Define Relative Humidity?

Answer 25

The amount of Water Vapour present in the air, expressed as a percentage of the amount required to reach saturation at the same Temperature.

Question 26

When the Temperature of the Air decreases, Relative Humidity ‘____’?

Answer 26

Increases.

Question 27

When the Temperature of the Air increases, Relative Humidity ‘____’?

Answer 27

Decreases.

Question 28

Define Dew Point?

Answer 28

The Temperature to which air must be cooled for it to become saturated.

Question 29

What is the formula to calculate Cloud Base?

Answer 29

(Temperature – Dew Point) x 400.

Question 30

When the Temperature value is higher than the Dew Point value, what are the conditions of the current Air?

Answer 30

• Dry Air.

- Clear Skies.

Question 31

When the Dew Point value is close to the Temperature value, what are the conditions of the current Air?

Answer 31

• Humid Air.

- Low Cloud.

Question 32

When the Dew Point and Temperature values are equal, what are the conditions of the current Air?

Answer 32

• Saturated Air.

- Fog and Mist.