Michigan Test for Teacher Certification (MTTC) Secondary Integrated Science Practice test

What is the function of a psychrometer?

1. Measuring wind speed and direction

2. Measuring air pressure

3. Measuring humidity

4. Measuring temperature

The correct answer is: Measuring humidity

A psychrometer is specifically designed to measure humidity, which is the amount of water vapor present in the air. It typically consists of two thermometers: one with a dry bulb that measures air temperature and another with a wet bulb that has a wick that is moistened. The evaporation of water from the wet bulb lowers its temperature; the difference in temperature readings between the two thermometers allows for the calculation of relative humidity. This instrument is commonly used in meteorology and various environmental sciences to assess moisture content in the atmosphere, which is crucial for understanding weather patterns, climate conditions, and humidity's impact on comfort levels in human environments. In contrast, other options, like measuring wind speed, air pressure, or temperature, involve different instruments such as an anemometer for wind, a barometer for air pressure, and a standard thermometer for temperature. Therefore, the role of a psychrometer is distinctly focused on assessing humidity levels.