Question

Which of the following is wrongly matched?
(A) Barometer-pressure
(B) Lactometer-milk
(C) Coulomb’s law-charges
(D) Humidity-Calorimeter

Answer 1

Hint We are given different instruments and what they are used for. We have to find out which one is not matched to its correct use. For that, we need to know the relation between the given pairs. If we know the use of each instrument then we can find the wrongly matched pair.

Complete Step by step solution
A barometer is an instrument used for measuring pressure. Hence the first option is correctly matched. The purity of milk is measured using an instrument called a lactometer. So the second option is also correctly matched. We know that coulomb’s law is associated with electric charges. Therefore we can say that the third option is also correctly matched. This leaves us with the fourth option. A calorimeter is used for measuring the heat of physical changes or chemical reactions. But in the option, it is paired with humidity. This is a wrong match since the calorimeter has nothing to do with humidity.
The answer is:

Option (D): Humidity-Calorimeter

Additional information
The instrument used to measure the content of water vapor, in air, soil, and other spaces is called a hygrometer. To measure the humidity a humidity sensor or a humidity detector is used.

Note
Barometer, lactometer, and calorimeter are instruments and Coulomb's law is a law. This could create confusion in students. Since the three options other than Coulomb’s law gives the relation between an instrument and the quantity measured. One can be easily misled by thinking option (C) is the wrongly matched pair. But we know that Coulomb’s law is associated with charge. This should be taken carefully