Advertisements
Advertisements
Question
How will you show that there is vacuum above the surface of mercury in a barometer? What name is given to this vacuum?
Advertisements
Solution
The space above mercury is a vacuum. This empty space is called 'Torricellian vacuum'.
This can be shown by tilting the tube till the mercury fills the tube completely. Again when the mercury column becomes stationary, the empty space is created above the mercury column. If somehow air enters into the empty space or a drop of water gets into the tube, it will immediately vaporize and the air will exert pressure on mercury column due to which the barometric height will decrease.
RELATED QUESTIONS
The atmospheric pressure is nearly 105 Pa.
The atmospheric pressure on earth surface is nearly .............. .
Describe a simple experiment to illustrate that air exerts pressure.
Give reason for the following:
Water does not run out of a dropper unless its rubber bulb is pressed.
What do you understand by atmospheric pressure?
Write the numerical value of the atmospheric pressure on the surface of earth in pascal.
Give two reasons for use of mercury as a barometric liquid.
Convert 1 mm of Hg into pascal. Take density of Hg = 13.6 x 103 kg m-3 and g = 9.8 m s-2 .
How does the atmospheric pressure change with altitude?
What effect does temperature have on air pressure?
