is it only the thermal kinetic energy of electrons that cause seeback effect..if it were so then why do we join two 'different' metals to form the junctions that are kept at different temperatures??

Question

ujjwal · Answer

because we need metals of different values of work function.. then only electron from one metal can diffuse to another metal (from the one having lower work function to the one having higher work function).. the electron diffusion takes place at both hot and cold junction .. but more electron diffusion takes place at hot junction.. so, a potential difference is created across two junctions.. and since there is a potential difference, current flows accordingly.. 
try to visualise all these, you will definately understand the phenomenon..

anonymous · Answer

the problem is how is the circuit completed..if it were so ten in both metals electrons should always go to colder side making hotter end positive and ultimately stopping the whole current flow

ujjwal · Answer

do you know what is work function?? it is not simply thermal energy gained by electron which causes  current to flow.. there is more to seebeck effect...

anonymous · Answer

geez u gotta take a look at seeback effet man..i 'm Not asking about photoelectric effect...

ujjwal · Answer

haha, it involves concept of work function too buddy.. trust me..

anonymous · Answer

k let me first research some docs involving that..

ujjwal · Answer

sure.. that would be helpful..