Chapter U3.5, Problem 2E

Interpretation Introduction

Interpretation : Advantages of Kelvin scale over the Celsius scale are to be discussed.

Concept Introduction : Several scales are designed to measure temperatures. Scales show numerical values corresponding to temperatures. Kelvin temperature scale was proposed by Lord Kelvin in 1848.

Answer to Problem 2E

Advantages of Kelvin scale over the Celsius scale are:

• In Kelvin scale the zero is set as the temperature of absolute zero. In Celsius scale, the melting temperature of ice is set as 0⁰C and boiling point of water is 100⁰C.
• Kelvin scale is based on absolute temperature which is required by universal gas laws. There is no place for absolute zero in Celsius scale.
• In Kelvin scale the symbol for degree, 0, is not used while in Celsius scale the symbol is used. So Kelvin is more convenient to write.
• The S.I unit of temperature is Kelvin.

Explanation of Solution

In Kelvin scale, the zero is set as the temperature of absolute zero. This results in all temperatures to be positive when they are expressed in Kelvin. In Celsius scale the melting temperature of ice is 0⁰C and boiling point of water is 100⁰C. It can have negative temperatures.Kelvin scale is based on absolute temperature which is required by universal gas laws. There is no place for absolute zero in Celsius scale.In Kelvin scale the symbol for degree, 0, is not used while in Celsius scale the symbol is used. So Kelvin is more convenient to write. The S.I unit of temperature is Kelvin.

Conclusion

Two commonly used scales are the Celsius scale and the Kelvin scale. One can convert a temperature in Celsius to that in Kelvin by simply adding 273 to the temperature in Celsius.