Which of the following devices uses Archimedes principle?

Correct option is B

The correct answer is (b) Hydrometer.
· A hydrometer is an instrument that measures the density or specific gravity of liquids. It works based on Archimedes' principle, which states that a body immersed in a fluid experiences an upward force equal to the weight of the fluid displaced by the body. The hydrometer floats at different levels in liquids of different densities.
Information Booster:
· Hygrometer: Measures the humidity of the air, not related to Archimedes' principle.
· Barometer: Measures atmospheric pressure, typically using a column of mercury, not Archimedes' principle.
· Thermometer: Measures temperature, generally not based on Archimedes' principle.