Question 477General Subjects - Assistant Engineer

The correct answer is B) 45 grains of moisture per pound of dry air. Referring to the psychrometric chart, if the dry bulb temperature is 70°F and the relative humidity is 50%, the absolute humidity can be determined by finding the intersection of these values on the chart. At 70°F and 50% relative humidity, the absolute humidity is approximately 45 grains of moisture per pound of dry air. The other options are incorrect because they do not accurately represent the absolute humidity value corresponding to the given dry bulb temperature and relative humidity. The psychrometric chart is the standard tool used to determine various air properties, including absolute humidity, based on the known dry bulb temperature and relative humidity.