Question

What are different scales of temperature? 

What is the relation between them?

Answer 1

1. Celsius scale :

• The ice point (melting point of pure ice) is marked as O°C (lower point) and steam point (boiling point of water) is marked as 100°C (higher point). 
• Both are taken at one atmospheric pressure. 
• The interval between these points is divided into two equal parts. Each of these parts is called as one degree celsius and it is ‘written as 1 °C.

 2. Fahrenheit scale : 

• The ice point (melting point of pure ice) is marked as 32°F and steam point (boiling point of water) is marked as 212°F. 
• The interval between these two reference points is divided into 180 equal parts. Each part is called as degree fahrenheit and is written as 1°F.

 3. Kelvin scale :

The temperature scale that has its zero at -273.15°C and temperature intervals are same as that on the Celsius scale is called as kelvin scale or absolute scale.

The absolute temperature, T and celsius temperature, T_C are related as,

Relation between different scales of temperature:

where,

T_F = temperature in fahrenheit scale, 

T_C = temperature in celsius scale, 

T_K = temperature in kelvin scale, 

[Note: At zero of the kelvin scale, every substance in nature has the least possible activity.]