Which has a better conductivity for electricity: Thin or Thick Copper? Why? any references? thank you. )
thick copper will have the better conductivity, because there is a greater cross section of material for free electrons to travel. (thin wires have higher resistance). There is an equation that relates the resistance of a conductor to its resistivity. I think its R L*rho/A where R is resistance, L is length of the conductor, rho is the resistivity, and A is the cross-sectional area. For copper, the value of rho is a constant.
The first answer is correct for direct current. For alternating current at higher frequencies, skin effect forces most of the current to the surface. For a given mass of copper per unit length, a hollow tube or stranded wire has higher conductivity than a single solid conductor.
The answer really depends on whether you need to be careful about definitions. Thick copper has lower resistance than thin copper, since it is like having multiple sheets of thin copper in parallel. Thick copper therefore has higher conductance than thin copper. On the other hand, by strict definitions, the two will have equivalent conductivity, which is an intrinsic property and not normally dependent on the geometry. Of course, there are exceptions (reduced dimensionality, really high frequencies, super low temperatures, etc.) where the two could have different conductivities, but you can almost certainly ignore these.
