Question

If the cold junction of a thermo-couple is kept at $0^{\circ} C$ and the hot junction is kept at $T^{\circ} C$, then the relation between neutral temperature $\left(T_{n}\right)$ and temperature of inversion $\left(T_{i}\right)$ is

• A. $T _{ n }=\frac{ T _{i}}{2}$
• B. $T _{ n }=2 T _{ i }$
• C. $T _{ n }= T _{ i }- T$
• D. $T_{n}=T_{i}+T$

Answer 1

Answer: (A)

$T _{ n }=\frac{ T _{i}}{2}$

Answer 2

It is found that temperature of inversion $\left(T_{i}\right)$ is as much above the neutral temperature $\left(T_{n}\right)$ as neutral temperature is above the temperature of the cold junction $(T), i e$, $T_{i}-T_{n} =T_{n}-T$ $T_{i} =2 T_{n}-T$ But, here the cold junction is kept at $0^{\circ} C$, hence $T=0$. Thus, $T_{i}=2 T_{n}$ $T_{n}=\frac{T_{i}}{2}$