When there is a large difference in the reading of the dry and wet bulb thermometers, it shows that relative humidity is

Answer Details

The dry and wet bulb thermometers are used to measure relative humidity, which is the amount of moisture present in the air. When there is a large difference in the readings of the two thermometers, it means that the air is dry because the moisture from the wet bulb evaporates quickly due to low humidity. Thus, it indicates that the relative humidity is low. On the other hand, when the readings are closer, it indicates that the air is more saturated with moisture, and the relative humidity is higher. Therefore, the correct answer is "low."