Question { 7777 }

which is the device working in the three logic levels

Answer

ex-or gate

Question { 7413 }

why thermocouple called thermocouple?

Answer

akshay it is exactly correct ,

BUT i can say briefly,
1.the temperature measuring element formed of TWO DISSIMILAR METALS OF DIFFERENT ELEC PROPERTIES COPUPLED TOGETHER ,
2. MAIN PRINCIPLE/ PHENOMENA IN THIS MEASUREMENT IS CONDUCTION PROPERTIES OF METAL (acc to MATERIAL SCIENCE & THERMODYNAMICS ),
3.CHANGE IN THE ELEC PROPERTIES i.e .FLOW OF EMF THROUGH THE METAL WEN IT IS SUBJECTED TO TEMPERATURE DUE TO THE TEMP & ELEC PROPERTIES CHANGE.and diff metals hav diff elec properties.
4.so wen we join these metals , and apply temp to these metals ,they produces the differential voltage produced through them i.e . let us say metal 1 produce e1 , sim`ly metal2 produces e2 ,therefore net voltage produced is e12=e1-e2 or e2-e1
5.not all metals r suitable for thermocouples,those suitable which their elec properties changes with temp