Suppose it is snowing outside and the air is saturated.The air temperature and dew point are both 15°F,and the actual vapor pressure is 3 mb.If this air is brought indoors and warmed to 75°F,what would the relative humidity of this air be,assuming that its moisture content does not change? (The saturation vapor pressure at 75°F is 30 mb).
A)5 percent
B)10 percent
C)30 percent
D)50 percent
E)100 percent

Question

Suppose it is snowing outside and the air is saturated.The air temperature and dew point are both 15°F,and the actual vapor pressure is 3 mb.If this air is brought indoors and warmed to 75°F,what would the relative humidity of this air be,assuming that its moisture content does not change? (The saturation vapor pressure at 75°F is 30 mb).​
A)5 percent
B)10 percent
C)​30 percent
D)​50 percent
E)​100 percent

Quizplus · Accepted Answer

First, we need to calculate the saturation vapor pressure at 15°F, which can be done using a vapor pressure chart or formula. The saturation vapor pressure at 15°F is approximately 0.5 mb. 
Then, we can calculate the relative humidity of the air outside by dividing the actual vapor pressure (3 mb) by the saturation vapor pressure (0.5 mb) and multiplying by 100. 
RH = (3/0.5) x 100 = 600%
Since the RH cannot be above 100%, we know that the air is supersaturated and is in the process of forming precipitation (snow). 
When this air is brought indoors and warmed to 75°F, the saturation vapor pressure increases to 30 mb. Since the moisture content of the air does not change, the actual vapor pressure remains at 3 mb. 
Thus, the relative humidity indoors can be calculated by dividing the actual vapor pressure (3 mb) by the saturation vapor pressure (30 mb) and multiplying by 100. 
RH = (3/30) x 100 = 10%
Therefore, the correct answer is B) 10 percent.

Suppose It Is Snowing Outside and the Air Is Saturated