Question

The e.m.f. developed in a thermo-couple is given by $E=\alpha T+\frac{1}{2}\beta T^2$
where T is the temperature of hot junction, cold junction being at $0^{o}C$.

The thermo electric power of the couple is

• A. $\alpha +\frac{\beta }{2}T$
• B. $\alpha +\beta T$
• C. $\frac{\alpha T^2}{2}+\frac{\beta T^3}{6}$
• D. $\frac{\alpha }{2\beta }$

Answer 1

The correct option is B $\alpha +\beta T$

Given: $E=\alpha T+\frac{1}{2}\beta T^2$
Themoelectric power $=\frac{dE}{dT}=\alpha +\beta T$