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| Kelvin Scale of Temperature |
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| Lord Kelvin (1824-1907) devised this scale of temperature. Hence, this is called the Kelvin scale, and in this scale, temperature is expressed in Kelvin. In SI system, Kelvin is the unit of temperature. In this scale of temperature, zero of the scale corresponds to -2730C, which is said to be the temperature at which the volume of a gas reduces to zero. Hence, -2730C is also known as the absolute zero. For the same reason, this scale of temperature is also known as absolute scale of temperature. On this scale, the lower fixed point i.e. the temperature of melting ice at normal pressure is +273K and the upper fixed point ie,. the temperature of boiling water at normal pressure is 373K. The magnitude of each Kelvin is same as the magnitude of 10C. |
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| If TK represents a temperature on Kelvin scale and t0C represents the same temperature on Celsius scale, then (TK = t0C +273 or t0C = TK- 273) |
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| Example: |
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| 1) Express 370C in Kelvin Scale |
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| TK = t0C+273 = 37 + 273 |
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| T = 310 K |
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| 2) Express 543 K in Celsius scale |
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| t0C = TK-273 |
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| = 543 - 273 |
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| t = 2700C |
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