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NEET-XII-Physics
33: Thermal and Chemical Effects of Electric Current
- #15Find the neutral temperature and inversion temperature of a copper-iron thermocouple if the reference junction is kept at 0°C. Use the data in the table (33.1).Ans : Neutral temperature,
`` {\theta }_{n}=-\frac{a}{b}``
`` {a}_{CuFe}={a}_{CuPb}-{a}_{FePb}``
`` =2.76-16.6=13.84\,\mathrm{\,\mu V\,}°{\,\mathrm{\,C\,}}^{-1}``
`` {b}_{CuFe}={b}_{CuPb}-{b}_{FePb}``
`` =0.012+0.030=0.042\,\mathrm{\,\mu V\,}°{\,\mathrm{\,C\,}}^{-2}``
Thus, the neutral temperature,
`` {\theta }_{n}=\frac{-{a}_{CuFe}}{{b}_{CuFe}}=\frac{13.84}{0.042}=329.52°\,\mathrm{\,C\,}=330°\,\mathrm{\,C\,}``
The inversion temperature is double the neutral temperature, i.e. 659 `` °``C.
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