​It is an instrument for measuring wind force.​

Correct option is D

Correct Answer:(d) Wind anemometer

Explanation:
The wind anemometer is an instrument used to measure wind speed and force. It is widely used in meteorology, aviation, and environmental studies to monitor and analyze wind patterns and weather conditions.

Key Points for Exam:
● Instrument Name: Wind anemometer.
● Purpose: Measures wind speed and force.
● Fields of Use: Meteorology, aviation, and environmental studies.
● Types of Anemometers:

Cup anemometer (most commonly used).
Hot-wire anemometer (temperature-based).
Ultrasonic anemometer (uses sound waves).
Other Options Explained:
Bolometer: Measures heat or radiation intensity.
Hygrometer: Measures air humidity.
Salinometer: Measures salt concentration in liquids.
The wind anemometer plays a crucial role in weather forecasting and analyzing wind-related environmental factors.