what is thermocouple and what is thermo emf?

A thermocouple is a simple arrangement of two wires joined and they are connected to a high resistance millivoltmeter (Refer image given) . Thermocouples are superior to other thermometers as they can measure temperatures that fluctuate spontaneously. In the arrangement shown we see that the cold junction acts as a reference junction, while the hot junction is used to measure temperature. The EMF(E) developed is the thermoemf as given: Thanks & Regards, Vasantha Sivaraj, askIITians faculty