Question

The constants a and b for the pair silver-lead are 2.50 $\mu V{/}^o{C}^{-1}$ and 0.012 $\mu V/{(}^{o}C{)}^{-2}$ respectively. For a silver-lead thermocouple with colder junction at 0${}^{o}C$.

• A. there will be no neutral temperature
• B. there will be no inversion temperature
• C. there will not be any thermo-emf even if the junctions are kept at different tempeatures
• D. there will be no current in the thermocouple even if the junctions are kept at different temperatures

Answer 1

Answer: (A), (B)

The correct options are
A there will be no neutral temperature
B there will be no inversion temperature

Here, for For a silver-lead thermocouple with colder junction at $0^{\circ }C$
${\theta }_n=-\frac{a}{b}$

${\theta }_n=-\frac{2.50}{0.012}=-{208.3}^{\circ }C$

Also, for inversion ${\theta }_i=-\frac{2\times 2.50}{0.012}=-{416.6}^{\circ }C$
Hence, there will be no neutral temperature and no inversion temperature.