Classification - Verbal and Reasoning

Directions to SolveIn each of the following questions, certain 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.
Q1:

Choose the pair in which the words are differently related from the rest.

A Pyroheliometer : Radiation

B Calorimeter : Heat

C Planimeter : Area

D Barometer : Humidity

ANS:D - Barometer : Humidity

Explanation: In all other pairs, first is an instrument used to measure the second.