What is Atmospheric PRESSURE ?

In simple words , atmospheric pressure is non other than a pressure exerted by atmosphere.

The atmosphere , in which we are surrounded with , extends upto a height of 300km. It is FILLED with various gases. The pressure exerted by these atmospheric gases surrounding is called atmospheric pressure.

Factors determining the horizontal distribution of pressure are :

• Thrust

• Wind

• Temperature

• Force

• Season

• Volume

☞The atmospheric pressure is expressed in units of atmosphere , written as "atm".

☞ FORMULA for measuring atmospheric pressure = p = hdg. Here, p = pressure. h = height of the column. d = density of mercury. g = gravitation , USUALLY taken as (9.8 m/s^2)

☞ There are other units too , which are used to measure atmospheric pressure. They are 'torr' and 'bar'.

☞ 1 torr is denoted as 1mm of Hg.

☞ whereas , 1 bar is denoted as 10^5 Pa.

And also ,

☞ 1 atm = 1.013 bar.

Now , LET's learn about some devices used to measure atmospheric pressure.

1. Torricellian Barometer.

2. Fortune barometer.

3. Aneroid Barometer.