Question

can the dew point temperature be greater than the air temperature? no as this would mean that the air holds more water vapor than it can, yes as the dew point temperature does not depend on the air temperature, yes as the dew point temperature depends only on the humidity, no as this would mean that the air does not hold any water vapor

Answer 1

Correct choice: "no — as this would mean that the air holds more water vapor than it can."

Explanation: the dew point is the temperature to which air must be cooled (at constant water vapor content) for saturation (relative humidity = 100%) to occur. If the dew point were greater than the air temperature, the actual vapor pressure would exceed the saturation vapor pressure at the air temperature — i.e., relative humidity > 100% (supersaturation). Supersaturation can occur briefly in special conditions, but under normal conditions condensation happens first, so dew point is not greater than air temperature.

(Also note: dew point depends on the actual water vapor content — the vapor pressure or absolute humidity — not directly on the air temperature.)