Question 220General Subjects - 1st Asst/Chief

The correct answer is C) When the air is completely saturated with moisture and the relative humidity is 100%. This is correct because when the air is completely saturated with moisture, the relative humidity is 100%, and the dry bulb, wet bulb, and dew point temperatures are all equal. In this situation, the air cannot hold any more moisture, so the temperatures measured by the dry bulb, wet bulb, and dew point thermometers will be the same. The other options are incorrect because A) a relative humidity of 0% would mean the air is completely dry, not saturated, B) it is possible for the three temperatures to be equal under the right conditions, and D) zero grains of moisture per pound of dry air would also mean the air is completely dry, not saturated.