Question

Which temperature scale is the primary unit of measurement and analysis in the physical world?
A. Celsius Scale
B. Kelvin scale
C. Fahrenheit Scale
D. None of these

Answer 1

Temperature is an expression of a heat energy. There are three scales to measure the temperature i.e., Celsius, Kelvin and Fahrenheit. The Celsius Scale uses boiling point of water as a concept for quantifying temperature. But this can vary when the atmospheric pressure changes.

Complete step by step answer:
The temperature quantifies the hotness or coldness, an application of a temperature scale is the thermometer. The different temperature scales are
A. Celsius Temperature Scales: The Celsius scale finds application all around the world for both commercial and scientific measurements of temperature. Here, the temperature is represented as degrees Celsius $^{{^\circ }}{{C}}$.
In the Celsius scale, the freezing temperature of the water is ${{{0}}^{{o}}}{{C}}$. And the boiling temperature of the water is as $100$-degree Celsius.
Here, division of the interval between the upper and lower fixed point takes place into 100 equal parts, thus Celsius scale has $100$ equal parts between ${{{0}}^{{o}}}{{C}}$ and ${100^ \circ }{{C}}$.
B. Fahrenheit Temperature Scales: The temperature is represented as $^{{0}}{{F}}$ or degrees Fahrenheit. Here, freezing temperature of the water is as ${{32}}{{{0}}^{{^\circ }}}{{F}}$ and boiling temperature of the water is taken as ${2120^{{^\circ }}}{{F}}$ .
The relation between the Fahrenheit scale and Celsius scale is,
${{1000}}{{{ }}^{{^\circ }}}{{C = 212}}{{{0}}^{{^\circ }}}{{F }}$ and ${{{0}}^{{^\circ }}}{{C = 32}}{{{0}}^{{^\circ }}}{{F}}$
Kelvin scale: The derivation of the Kelvin scale is obtained from the Celsius scale, it does not use degrees and is represented as Kelvin or K. The concept of Absolute Zero is the basis of the Kelvin scale. The temperature at which everything freezes is absolute Zero. Molecules have the lowest energy at absolute zero.
Kelvin scale is used as SI (standard international) unit for the measurement of temperature.
The boiling point of water may vary when the atmospheric pressure changes. This is the reason why Celsius is not the SI unit for measuring temperature.

So, the correct answer is Option B.

Note: Some areas of engineering, another absolute temperature scale called the Rankine scale is preferred over the Kelvin scale. Its unit of measure is the degree Rankine $\left( {{{^\circ R}}} \right)$. The conversion of kelvin to $^{{^\circ }}{{C}}$ is, (Temperature in Kelvin $-{{ }}273.15$) and $^{{^\circ }}{{C}}$ to kelvin is (Temperature in degrees Centigrade $+ {{ }}273.15$).