Answer: The correct answer is-
2.psychrometer - weather front speed.
Psychrometer is one of the types of weather instruments that is used to measure the relative humidity by using two different thermometers that are-
A thermometer with dry bulb ( which measures the temperature) and a wet bulb thermometer ( which measures the temperature when the bulb is dipped inside a liquid).
The results of these two thermometers ( particularly the difference in the temperature) is then used in determining the relative humidity of the surrounding area.
Thus, option 2) is incorrectly matched.
