what was his job at bell labs?
He was a member of a solid-state physics group where they were to seek a solid-state alternative to fragile glass vacuum tube amplifiers.
John Bardeen
In October 1945, Bardeen began work at Bell Labs. He was a member of a solid-state physics group, led by William Shockley and chemist Stanley Morgan. Other personnel working in the group were Walter Brattain, physicist Gerald Pearson, chemist Robert Gibney, electronics expert Hilbert Moore and several technicians. He moved his family to Summit, New Jersey.

The assignment of the group was to seek a solid-state alternative to fragile glass vacuum tube amplifiers. 
what is distributed-element circuit? They are electrical circuits composed of lengths of transmission lines or other distributed components. what are some active components in it? diodes, transistors mention a few of the circuit's disadvantages? It takes up more space than lumped-element circuits and is problematic in hand-held mobile devices which has limited space. what is the second active component? It is a semiconductor device used to amplify or switch electronic signals and electrical power. how is it in comparison to the vacuum tubes? UNANSWERABLE what are its various types? MOSFET (metal–oxide–semiconductor field-effect transistor) what problems are faced during transistor's naming? With so many independent naming schemes, and the abbreviation of part numbers when printed on the devices, ambiguity sometimes occurs. when was the first transistor developed? 1947 in which lab, or, in which place was it developed? Bell Labs who was the person that developed it? John Bardeen and Walter Brattain what was the relationship between xerox and the first person? Bardeen was also an important adviser to Xerox Corporation. state a theory proposed by him? BCS theory what is that theory about? Superconductivity and what is it? A set of physical properties observed in certain materials where electrical resistance vanishes and magnetic flux fields are expelled from the material. how many times did he win nobel prize? Twice - in 1956 and in 1972
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John Bardeen [SEP] Bell Labs
The pace of the work picked up significantly when they started to surround point contacts between the semiconductor and the conducting wires with electrolytes. Moore built a circuit that allowed them to vary the frequency of the input signal easily and suggested that they use glycol borate (gu), a viscous chemical that didn't evaporate. Finally they began to get some evidence of power amplification when Pearson, acting on a suggestion by Shockley, put a voltage on a droplet of gu placed across a p–n junction.