Physics
How will you show there is vacuum above the surface of mercury in a barometer? What name is given to this vacuum ?
Answer
In an accurate barometer, the empty space above the mercury in the tube is perfect vacuum. If somehow air enters the empty space or a drop of water (or liquid) gets into the tube, it will immediately change into vapour in the vacuum space and the air (or the vapours of liquid) will exert pressure on the mercury column due to which the barometric height will decrease.
Such a barometer is a faulty barometer and it's barometric height will be less than the actual atmospheric pressure.
The name given to this space is torricellian vacuum.
Related Questions
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