Question

The SI unit of atmospheric pressure is ________

Answer 1

Hint: Pressure is defined as the force applied on a surface per unit area. Different units are used to measure pressure. Atmospheric pressure is due to weight of atmosphere and is measured using different units than pascal.

Complete step by step solution:
There are many units used for measuring pressure. The S.I unit of pressure is pascal (Pa). 1Pa=1 newton per square meter.
Atmospheric pressure is defined as the pressure exerted by the atmosphere due to its weight. The S.I unit of atmospheric pressure is atm pronounced as atmospheres. It is related to other units of pressure as follows:
1 atm = 101325 Pa
Torr is another unit of pressure which is defined on an absolute scale such that 1 atm = 760 torr.

Additional information:
Barometer is a device used to measure atmospheric pressure at a place. In a barometer, there is a mercury column in which mercury moves up or down depending on atmospheric pressure at a place. It is graduated in millimetres and the unit used for measurements from a barometer is mm Hg.
1mm of Hg = 133.3224 Pa
The atmospheric pressure at the sea level is 76mm of Hg.

Note: The atmospheric pressure is maximum at the sea level. The reason for this is that pressure decreases with increase in height in the atmosphere and atmospheric depth is maximum at the sea level. Under the sea level, pressure increases at greater speed because water exerts additional pressure and pressure increases by 1atm after every 10m depth under the sea level.