question_answer

In the Seebeck series bismuth occurs first followed by Cu and Fe among other. The Sb is the last in series. If \[{{V}_{1}}\] be the thermo emf at the given temperature difference for Bi-Sb thermocouple and \[{{V}_{2}}\]be that for Cu-Fe thermocouple, then :

A)  \[{{V}_{1}}=\text{ }{{V}_{2}}\]                                                   

B)  \[{{V}_{1}}<\text{ }{{V}_{2}}\]

C)  \[{{V}_{1}}>\text{ }{{V}_{2}}\]                                 

D)  data insufficient

Correct Answer: C

Solution :

                Thermocouple thermometer is based on Seebeck effect. For a given difference of temperature  of  two  junctions  of  a thermocouple, the larger is the separation between the metals of Seebeck series, the greater is the thermo emf produced.