Question

The terms used for production and measurement of very low temperature (below boiling point of ${{\text{N}}_2}$, i.e. $77{\text{K}}$) and very high temperature $\left( { < 1000{\text{K}}} \right)$ are respectively called:
A. cryogenics, pyrometry.
B. pyrometry, cryogenics.
C. thermometry, pyrometry.
D. coulometry, pyrometry.

Answer 1

Hint: There are different processes by which temperatures are measured. Some are meant for low temperatures and others are for high temperatures. Thermometers are used for measuring body temperature which is the normal temperature.

Complete step by step answer:
Temperature is a measure proportional to the average translational kinetic energy associated with the disordered microscopic motion of atoms and molecules. The flow of heat is from high temperature to low temperature. Temperatures can be measured in different units like Celsius, Kelvin, Fahrenheit, Rankine etc. Temperatures can be measured using different devices like bimetallic thermometer, glass thermometer, electrical temperature instruments, etc. All of them are based on different phenomena.
A. The word cryo means cold. Cryogenics is the study of low temperature and behavior of material under these low temperatures. This process has a unique ability to recycle materials which are difficult to separate. The temperature as low as $ - {180^ \circ }{\text{C}}$ is attained in the cryogenic system.
Pyrometry is the method in which relatively high temperatures are measured. For example to measure temperature in furnaces. Since the process involves measuring the radiation, we do not have to touch the material being measured.
C. Thermometry is used to measure normal temperatures like body temperatures.
D. Coulometry is used to measure the quantity of electrical charge that passes through a solution during an electrochemical reaction.
Hence, Option A is the correct option.

Additional information:
There are a lot of applications for cryogens.
-Aerospace-cryogenic rocket engine
-Manufacturing field
-Medical field
-Electronics

Note:
The extremely low temperatures are produced by using the substances called cryogens. Some examples of cryogens are liquid nitrogen and liquid helium. Cryogens are stored in vessels which provide good insulation.
Pyrometry process works by radiation from the system.