School of Physics Lecture Demonstration Manual

Eg-1 Magnetic Field of a Large Thermoelectric Current

Published: Tuesday 14 March 2006 - Updated: Tuesday 29 March 2011


To demonstrate a unique application of thermoelectric currents.



Click on pictures to enlarge.

M-Field of Thermoelectric Current Diagram


A thermocouple that will produce currents of approximately 100 Amperes in a very low resistance circuit ( ~ 0.0001 ohms) if one end is cooled and the other heated over a bunsen burner.

This current can be demonstrated by its magnetic effects; a soft iron block with polished contact surfaces surrounding the thermocouple becomesan electromagnet that will easily carry a load of 5 kgwt although it is magnetised by only a single current carrying loop.

The thermocouple consists of Copper-Constantan.

Safety notes

Electrical safety 

Fire/Burn safety 

Sharps safety 


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