Width + density of wire

[nessi]

one more thing. Will resistance increase or decrease when the wire has a larger cross-section or higher density

[Gef]

The larger the cross section the lower the resistance - think of the current like water flowing through a pipe.

As for density I'm not sure but gold, with a relatively high density, is one of the best conductors.

[shammydodger]

Resistance decreases with increasing density. There are more metal atoms per unit volume, and thus more free electrons.

[mibn2cweus]

Short, fat, cold wire has the least resistance. Heating disturbs the atoms in a conductor and disrupts electron current flow increasing resistance.

>shape

It is not so much the density but the number of electrons in the outermost shell (valance ring) that determine conductance. Best conductors all have one loosely held valance electron; in order: Silver, Copper, Gold, Aluminum.

[nessi]

Thanks