Q. Thermoelectric constant of a thermocouple are $\alpha$ and $\beta.$ Thermoelectric power at inversion temperature is
A) $\alpha$
B) $- \alpha$
C) $\frac{\alpha}{\beta}$
D) $- \frac{\alpha}{\beta}$
Explanation
(b) $E = \alpha T + \frac{1}{2}\beta T^{2}$
For inversion temperature
$E = 0,\ \ T = \frac{- 2\alpha}{\beta}$
Thermo electric power
$P = \frac{dE}{dT} = \alpha + \frac{1}{2}\beta.(2T) \Rightarrow \alpha + \beta.T$
$\alpha + \beta\left( \frac{- 2\alpha}{\beta} \right) = \alpha - 2\alpha = - \alpha$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.