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

• A

  $\mathrm{\alpha }+\frac{\mathrm{\beta }}{2}\mathrm{T}$

• B

  $\mathrm{\alpha }+\mathrm{\beta T}$

• C

  $\frac{{\mathrm{\alpha T}}^2}{2}+\frac{{\mathrm{\beta T}}^3}{6}$

• D

  $\mathrm{\alpha }/2\mathrm{\beta }$