Question

Thermo electric thermometer is quick in action because the thermal capacity of the hot junction is
(A) Less
(B) More
(C) Equal
(D) Zero

Answer 1

Hint To answer this question we need to have the idea about the function of a thermo electric thermometer. We should also relate it with the thermal capacity of the hot junction.

Complete step by step answer
The thermo electric thermometer is used to find the temperature of a region, in which the hot junction of the thermometer is placed. This is achieved by setting up a thermo couple whose thermo emf generated is measured. This thermo emf is converted to the corresponding temperature by using the calibration curve. For being quick in action, the hot junction must be sensitive to small temperature changes. As we know that the thermal capacity is the quantity of heat required to raise the temperature of a body of unit mass by one unit temperature. So for the high sensitivity, the thermal capacity of the hot junction must be low.
Hence, the correct answer is option (A), less.

Note
The thermo electric thermometer is an important engineering device that is used for measuring high and low temperatures. It is based on the see back effect. It is used in a number of automatic control and monitoring systems. It is used in temperature management systems. It is widely used for energy recycling. It is used in thermoelectric generators, which are used as heat engines for converting the waste heat of the power plants into electric power. Also, it is used in automobiles to increase the fuel efficiency. It can measure all temperatures in the range of -200 degree Celsius to 1600 degree Celsius.