Question

Which of the following is a temperature measurement element?

• A. Thermocouple
• B. Pressure gauge
• C. Flow meter
• D. Tachometer

Hint:

Thermocouples convert temperature difference into voltage.

Answer 1

The Correct Option is A

Step 1: Identify the Seebeck effect as the basis.
When two dissimilar metals form a loop with their two junctions at different temperatures, an EMF (voltage) is generated. This is the Seebeck effect. The EMF depends directly on the temperature difference.

Step 2: Match the Seebeck effect to the thermocouple.
A thermocouple is constructed from two dissimilar metal wires joined at one end (the measuring junction). The EMF produced is calibrated to display temperature. No external power is needed.

Step 3: Eliminate the other options.
A pressure gauge uses elastic deformation, a flow meter uses fluid velocity, and a tachometer uses rotational speed. None exploit the Seebeck effect. Only the thermocouple is a temperature measurement element based on it. \[ \boxed{\text{Thermocouple}} \]