Question

1 Millibar is equals to:

Answer 1

Hint Since Bar is the unit of pressure, which is basically used by the department of weather forecasting for determining the atmospheric pressure. And N (newton) is SI unit of force. Thus, relate the formula of pressure in terms of force.

Complete Step By Step Solution
Now, generally, in previous junior classes also we all have studied that pascal is a unit of pressure. Pressure is nothing but “force per unit area”. It mainly describes the effect of pressure.
Mathematically,
$\Rightarrow pressure = \dfrac{{force}}{{area}}$
And in case of fluids, pressure is always determined by pascal. In more simple words, the unit of pressure in fluids is pascal (symbol is pa). One pascal is defined as the 1 Newton force applied on an area of 1 m2.
$\Rightarrow 1pascal = \dfrac{{1newton}}{{1{m^2}}}$ Or,
$\Rightarrow 1pascal(pa) = N{m^{ - 2}}$………………………………… eq.1
Pressure has many units, sometimes it’s measured in torr, bar or mm of Hg (mercury), some of these are derived from historical methods, some are used according to their own fields like bar and gauge and some of pressure units are adopted as per calculation convenience. Similarly, Bar is a commonly used unit of the pressure which is mostly used to measure atmospheric pressure.
Also, it’s experimentally calculated that,
$\Rightarrow 1bar = 100000N{m^{ - 2}}$Or
$\Rightarrow 1bar = {10^5}N{m^{ - 2}}$ (more convenient to us)
And $\Rightarrow 1millibar = {10^{ - 3}}bar$

$$\Rightarrow 1millibar = {10^{ - 3}} \times {10^5}pa \\\ \Rightarrow 1millibar = {10^{ - 3 + }}^5pa \\\ \Rightarrow 1millibar = {10^2}pa \\\$$

From eq.1, we can conclude that
$\Rightarrow 1millibar = {10^2}N{m^{ - 2}}$

Thus, option (i) is correct, i.e. 1millibar is equal to$100N{m^{ - 2}}$.

Note Milli in any unit is always equivalent to${10^{ - 3}}$ times of that unit. Similarly, mega =${10^6}$ and kilo =${10^3}$. Always try to relate the physical quantity on both the sides through any formula to find a relation between them.