Question

explain the working of mercury barometer ​

Answer 1

Principle of the mercury barometer. Air pressure at any level in the atmosphere depends on the weight of the air overhead. A mercury barometer is basically just a scale that measures the weight of the atmosphere above.

Answer 2

the mercury barometer used to measure to pressure . Torricellian barometer (sometimes called a mercury barometer) is an inverted (upside-down) glass tube standing in a bath of mercury. Air pressure pushes down on the surface of the mercury, making some rise up the tube. The greater the air pressure, the higher the mercury rises.