Earth Science worksheet
Topic: Relative Humidity
Relative Humidity
1

What is the relative humidity when the drybulb temperature is 16°C and the wet-bulb temperature is 10°C?

(1) 6%

(2) 14%

(3) 33%

(4) 45%

2

If air has a dry-bulb temperature of 2°C and a wet-bulb temperature of –2°C, what is the relative humidity?

(1) 11%

(2) 20%

(3) 36%

(4) 67%

3

The diagram below shows a weather instrument used to determine relative humidity.

What is the relative humidity?

(1) 40%

(2) 36%

(3) 8%

(4) 4%

Base your answers to questions 4 on the photographs below and on your knowledge of Earth science. One photograph shows a digital device that recorded several weather variables. The second photograph shows two weather instruments, labeled A and B.

4

Based on the outside air temperature and relative humidity shown on the digital device, what is the approximate dewpoint for the time shown on the device?

(1) 8°C

(2) 12°C

(3) 18°C

(4) 31°C

5

A dry-bulb temperature of 30°C and a wet-bulb temperature of 29°C were recorded at a weather station. What are the relative humidity and the most likely weather conditions?

(1) Relative humidity is 29% with clear skies.

(2) Relative humidity is 29% with a good chance of snow.

(3) Relative humidity is 93% with clear skies.

(4) Relative humidity is 93% with a good chance of rain.

6

What is the relative humidity if the dry-bulb temperature is 26°C and the wet-bulb temperature is 18°C?

(1) 13 %

(2) 33 %

(3) 45 %

(4) 51 %

7

What is the relative humidity if the dry-bulb temperature is 16°C and the wet-bulb temperature is 10°C?

(1) 45%

(2) 33%

(3) 14%

(4) 4%

8

The diagram below represents a sling psychrometer.

Based on the wet-bulb temperature and the dry-bulb temperature, what is the approximate relative humidity?

(1) 6%

(2) 8%

(3) 30%

(4) 60%

9

The diagram below represents the wet-bulb and dry-bulb temperatures on a sling psychrometer.

What was the relative humidity of the air when these temperatures were recorded?

(1) 5%

(2) 17%

(3) 20%

(4) 63%

10

The data table below shows the dry-bulb and wet-bulb temperatures measured with a psychrometer on four different days at the same location.

According to the data shown in the table, which day had the highest relative humidity?

(1) 1

(2) 2

(3) 3

(4) 4

Base your answers to questions 11 on the weather map below and on your knowledge of Earth science. On the weather map, the location of the center of a high-pressure system (H) and a front are shown. Isobar values are labeled in millibars (mb). Weather station models represent the weather conditions at Atlanta, Georgia, and Tampa, Florida.

11

Describe one piece of evidence shown on the map that indicates that Tampa, Florida, has a high probability of precipitation. [1]

Allow 1 credit. Acceptable responses include, but are not limited to:

• — The dewpoint and air temperature are close together./high relative humidity

• — 100% cloud cover/overcast

• — Tampa is close to a front.

• — The air pressure is low.

Base your answers to questions 12 on the diagram below, which shows the windward and leeward sides of a mountain range. Arrows show the movement of air over a mountain. Points A and B represent locations at sea level on Earth’s surface.

12

What is the relative humidity at the base (bottom) of the cloud on the windward side of the mountain? [1]

%

Allow 1 credit for 100%.

Base your answers to questions 13 on the diagram below and on your knowledge of Earth science. The diagram represents a weather balloon as it rises from Earth’s surface to 1000 meters (m). The air temperature and wet-bulb temperature values in degrees Celsius (°C) and the air pressure values in millibars (mb) are given for three altitudes.

13

Determine the dewpoint and the relative humidity of the air at Earth’s surface. [1]

Dewpoint: ______________°C Relative humidity: ________%

Allow 1 credit if both dewpoint and relative humidity are correct.

• Dewpoint: 8°C

• Relative humidity: 40%