Q. For a thermocouple, the neutral temperature is $270℃$ and the temperature of its cold junction is $20℃.$ If there is no deflection in the galvanometer, the temperature of the hot junction should be
A) $210℃$
B) $540℃$
C) $520℃$
D) $209℃$
Explanation
(c) When there is no deflection, then this temperature is called inversion temperature. It is given by the relation
$\theta_{n} = \frac{\theta_{i} + \theta_{c}}{2}$
Where $\theta_{c}$ is temperature of cold junction $= 20℃$ and neutral temperature $\theta_{n} = 270℃$
$\therefore\theta_{i} = 2\theta_{n} - \theta_{c} = 540 - 20 = 520℃$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.