Question

The CGS unit of 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. There exists units for pressure in the S.I. system as well as the C.G.S. system.

Complete step-by-step answer:
Pressure is defined as the force applied on a surface per unit area of the surface. The expression for pressure is
\[P = \dfrac{F}{A}\]
There are many units used for pressure. The S.I. a unit of pressure is pascal (Pascal is defined as the pressure due to a force of 1N on a surface having surface area equal to $1{m^2}$.
$\therefore 1Pa = 1N/{m^2}$
The C.G.S. unit of pressure is the bar. One bar is defined as the pressure exerted by a force of 1 dyne on an area equal to 1 $c{m^2}$.
$\therefore 1bar = 1dyne/c{m^2}$
Additional information:
The dimensional formula of pressure is$\left[ {{M^1}{L^{ - 1}}{T^{ - 2}}} \right]$.
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.
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 student should take care that while solving problems all the units of various quantities must be in the same system of units. The units of pressure in S.I. system can be related to units of pressure in C.G.S. system as follows:
$1bar = {10^5}Pa$