Question

Given below are two statements:
Statement (I): The direct measurement of relative humidity is done using hygrometer.
Statement (II): The most common method of measuring relative humidity is using dry and wet bulb thermometers.

In light of the above statements, choose the most appropriate answer from the options given below.

• A. Both Statement (I) and Statement (II) are correct.
• B. Both Statement (I) and Statement (II) are incorrect.
• C. Statement (I) is correct but Statement (II) is incorrect.
• D. Statement (I) is incorrect but Statement (II) is correct.

Hint:

While electronic hygrometers give direct digital readings, wet and dry-bulb thermometers are the primary calibration standards used to verify and build psychrometric charts.

Answer 1

The Correct Option is A

Step 1: Confirm Statement I by recalling what a hygrometer does.
A hygrometer is an instrument built to sense atmospheric moisture directly, using elements such as human hair or electronic capacitive sensors whose physical properties change with humidity, so it gives a direct reading of relative humidity. This matches Statement I, making it correct.
Step 2: Confirm Statement II by recalling the psychrometer method.
The dry and wet bulb thermometer arrangement, known as a psychrometer, is the most widely used field and laboratory method because it only needs two ordinary thermometers, one kept wet by a wick, and the difference between the two readings is looked up on a psychrometric chart or table to get relative humidity. Its simplicity and low cost make it the most common method in practice, so Statement II is also correct.
Step 3: Note that the two methods are complementary rather than contradictory.
One describes a direct sensing instrument and the other an indirect, calculation based method, and both coexist as valid, standard techniques rather than one disproving the other.
\[ \boxed{Both Statement (I) and Statement (II) are correct.} \]