Question 546General Subjects - Assistant Engineer

The correct answer is B) Thermocouple. A thermocouple is an electrical temperature transmitting system where the system voltage is generated by the magnitude of the temperature difference between the hot and cold junctions. This voltage is known as the Seebeck effect, which occurs when two dissimilar metals are joined together and exposed to a temperature gradient. The voltage generated is proportional to the temperature difference, making the thermocouple an effective method for measuring temperature. The other options are incorrect because a bimetallic sensor (A) uses the thermal expansion of two different metals to measure temperature, a thermistor (C) uses a temperature-dependent resistor, and a resistance temperature detector (D) uses the change in electrical resistance of a metal to measure temperature. These systems do not rely on the Seebeck effect to generate the system voltage.