Question

The cold junction of thermocouple is maintained at 10${}^o$C. No thermo e.m.f. is developed when the hot junction is maintained at 530${}^o$C. The neutral temperature is

• A. 260${}^o$C
• B. 265${}^o$C
• C. 270${}^o$C
• D. 520${}^o$C

Answer 1

The correct option is C 270${}^o$C

When thermo e.m.f. is zero, the corresponding temperature is the inversion temperature, ${\theta }_i$.
Here, ${\theta }_i={530}^{o}C$ and cold junction temp, ${\theta }_c={10}^{o}C$
We know that: neutral temp, ${\theta }_n=\frac{{\theta }_i+{\theta }_c}{2}=\frac{530+10}{2}={270}^{o}C$