Q. The neutral temperature $t_{n} = 285{^\circ}C$ is constant for a Cu-Fe thermocouple. When the cold junction is at $0{^\circ}C,$ the value of inversion temperature is $t_{i} = 570{^\circ}C$ but if the cold junction is at $10{^\circ}C,$ the inversion temperature $\left( t_{i} \right)$ will be
A) $550{^\circ}C$
B) $560{^\circ}C$
C) $570{^\circ}C$
D) $580{^\circ}C$
Explanation
(b) Neutral temperature, $t_{n} = \frac{t_{i}\ + {\ t}_{c}}{2}$
$\Rightarrow \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 285{^\circ} = \ \frac{t_{i}\ + 10{^\circ}}{2}$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 570{^\circ} = t_{i} + 10{^\circ}$
or $t_{i} = 560{^\circ}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.