Thermoelectric thermometer is based on:
A. Photoelectric Effect
B. Seebeck Effect
C. Compton Effect
D. Joule Effect

Hint: Thermoelectric thermometer is a special device which is used to measure low as well high temperature of an object or body. In thermoelectric thermometer different thermocouples are used for measuring the different range of temperature. Also here the concept of thermoelectricity is used.

Complete answer:
The concept we use in thermoelectric thermometer is thermoelectricity which occurs at junctions of dissimilar conductors or it may occur within the single conductor. In \[1821\] , Thomson Johann Seebeck observed a flow of electric current in the circuit made up of two conductors, when two junctions in the circuit were kept at different temperatures. The two junction is known as thermocouple and current flows through it is known as thermoelectric current. This is known as the Seebeck Effect.

According to this we can say that, when two different metals are joined together end to end. If one junction of thermocouple is kept at any fixed temperature which may be cold and another junction is kept in a hot region, then an e.m.f is developed between the junctions. The current which flows is called thermoelectric current. Thus we can say that the thermoelectric thermometer is based on the Seeback effect which helps in measuring temperature for different ranges of temperature.

Hence the correct option is B.

Note: The thermoelectric thermometer can be used for measuring different ranges of temperature. Copper couple is used for temperature range \[ - 200{{\text{ }}^ \circ }C\] to \[400{{\text{ }}^ \circ }C\]. The temperature of cold junction is kept at zero degree celsius and thus temperature of hot junction varies accordingly. The graph obtained between the temperature of the hot junction and e.m.f is known as the calibration curve.