Coast Guard Exams
Question 1225Navigation General70% to pass

Fog forms when the air temperature is at or below _______________.

AI Explanation
The correct answer is C) the dew point. Fog forms when the air temperature drops to or below the dew point, the temperature at which water vapor in the air condenses into tiny water droplets suspended in the atmosphere. This is the temperature at which the air becomes saturated with water vapor, leading to the formation of fog. The other options are incorrect because: A) 32°F is the freezing point of water, not the temperature at which fog forms. B) The dry bulb temperature is simply the air temperature, not the specific point at which fog occurs. D) The wet bulb temperature is related to evaporative cooling, not the direct formation of fog.

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