Physics 2005 JAMB Past Questions - Question 41: When the temperature difference between the wet and dry bulbs of a hygrometer is high, this indicates that

Correct Answer

C

Explanation

When the temperature difference between the wet and dry bulbs of a hygrometer is high, it indicates that the relative humidity in the air is low. The wet bulb temperature is typically lower than the dry bulb temperature because the evaporation of water from the wet bulb lowers its temperature. The greater the difference between these two temperatures, the drier the air is, which means that the air has a lower relative humidity. Conversely, when the temperature difference between the wet and dry bulbs is small, it suggests that the air has a higher relative humidity. Hygrometers, like sling psychrometers, use this principle to measure relative humidity.