A manometer is an instrument used for measuring
Relative density of liquid
Pressure in liquids and gases
Humidity
Atmospheric pressure
Correct answer is B
a manometer is used to measure pressure in liquids and gases. Manometer gauges measure the pressure of gases and vapors from atmospheric to about 1 Pa by balancing the force exerted by the gas or vapor against the weight of a column of liquid, usually mercury, water, or oil.