In the following question, pairs of words are given, out of which the words in all pairs except one, bear a certain common relationship. Choose the pair in which the words are differently related from the rest.
Choose the pair in which the words are differently related from the rest.
Pyroheliometer : Radiation
Calorimeter : Heat
Planimeter : Area
Barometer : Humidity
Correct answer is D
In all other pairs, first is an instrument used to measure the second.