Question

The S.I unit of pressure is Pascal.
A.)True
B.)False

Answer 1

 Hint: S.I unit of pressure can be found by using the S.I. units of force and area. As we know pressure is

$P=\dfrac{F}{A}$

So the S.I unit of pressure can be found by dividing S.I. unit of force and area. Pascal is the name given to unit

$Pa=\dfrac{N}{{{m}^{2}}}=\dfrac{Kg}{m{{s}^{2}}}$
Pascal is represented by

$Pa$

 Complete Step By Step Solution:

The S.I. base units are also known as fundamental units. These include kilogram, second, Ampere, meter, Kelvin, Mole and candela. S.I units of all other physical quantities are derived from them.
We know that pressure is thrust (force perpendicular to surface on which it is applied) per unit area. So, mathematically we can write

$P=\dfrac{F}{A}$
The S.I. unit of area is

${{m}^{2}}$

Force is the product of mass and acceleration. So, it's S.I. unit will be a product of S.I. unit of mass and S.I. unit of acceleration. Thus, S.I. unit of force will be
$kg\times \dfrac{m}{{{s}^{2}}}=\dfrac{kgm}{{{s}^{2}}}$
So, S.I. unit of pressure will be
$\dfrac{\dfrac{kgm}{{{s}^{2}}}}{{{m}^{2}}}=\dfrac{kg}{m{{s}^{2}}}$
 This unit is also called Pascal
Therefore the S.I unit of pressure is Pascal.
Hence the correct option is A.

Additional Information: Pressure has no direction associated with it. So pressure is a scalar quantity. A simple example of the importance of pressure is cutting fruits with a knife. Even on applying the same force as applied with a hand, it does not get cut. This is because surface area of knife is very less than that of hand, which increases pressure and cuts the fruit

Note: The S.I unit of pressure was given the name Pascal after the scientist Blaise Pascal in honor of his contribution to hydrodynamics, hydrostatics and experiments with barometers. Many other S.I. units are also named after other scientists in honor of their contribution to physics. For example, the S.I unit of force $\dfrac{kgm}{{{s}^{2}}}$ is called N in honor of great scientist Sir Isaac Newton. S.I unit of frequency ${{s}^{-1}}$ is called Hz in honor of scientist Heinrich Hertz. Dimension of pressure is

$M{{L}^{-1}}{{T}^{-2}}$