Question

1 mm Hg represents a pressure of
A. 760 atm
B. $\dfrac{1}{{760}}atm$
C. $\dfrac{1}{{76}}atm$
D. $\dfrac{1}{{76}} \times {10^{ - 2}}atm$

Answer 1

Recollect the definition of pressure and all its units. Also recall the definition of 1mm of Hg. Converting 1 mm of Hg to atm.Pressure is like a physical force exerted on an object or on anything. It is also called the force applied which is perpendicular to the surface of objects per unit area.
The SI unit of pressure is Pascal (Pa).There are different types of Pressures which are Absolute, Atmospheric, Differential, and Gauge Pressure.

Complete step by step answer:
From the above definition we can derive the following basic formula for pressure that is
$\dfrac{F}{A}$ (Force per unit area).
This unit of pressure is used because most barometers use mercury as the liquid. It is due to some of the properties of mercury. It is dense and has a low vapor pressure. The height of the liquid is often used as a measure of pressure.
Let us now define 1 mm of Hg.
A millimetre of mercury is a manometric unit of pressure.
I was formerly defined as the extra pressure generated by a column of mercury one millimetre high.
Whereas the current definition is exactly 133.322387415 pascals.
It is denoted mmHg or mm Hg.
Now let us understand what is atm.
Atmospheric pressure is abbreviated as atm. It is the pressure exerted by the weight of the atmosphere.
1mm of Hg is approximately 1/760 of standard atmospheric pressure.
That is 1 mm of Hg = $\dfrac{1}{{760}}atm$

So, the correct answer is Option b.

Note: There are various units of pressure and they have different conversions. 1 mm of Hg is defined as the extra pressure generated by a column of mercury one mm high.