NEET-XII-Physics
23: Heat and Temperature
- #4The pressure measured by a constant volume gas thermometer is 40 kPa at the triple point of water. What will be the pressure measured at the boiling point of water (100°C)?Ans : Given:
Pressure measured by a constant volume gas thermometer at the triple point of water, Ptr = 40 kPa = 40 × 103 Pa
Boiling point of water, T = 100°C = 373.16 K
Let the pressure measured at the boiling point of water be P.
For a constant volume gas thermometer, temperature-pressure relation is given below:
`` T=\frac{P}{{P}_{tr}}\times 273.16\,\mathrm{\,K\,}``
`` \Rightarrow P=\frac{T\times {P}_{tr}}{273.16}``
`` \Rightarrow P=\frac{373.16\times 40\times {10}^{3}}{273.16}``
`` \Rightarrow P=54643\,\mathrm{\,Pa\,}``
`` \Rightarrow P=54.6\times {10}^{3}\,\mathrm{\,Pa\,}``
`` \Rightarrow P\simeq 55\,\mathrm{\,kPa\,}``
Therefore, the pressure measured at the boiling point of water is 55 kPa.
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