Perhaps its true electric fields cannot exist inside of conductors.Maybe the ele
ID: 1794467 • Letter: P
Question
Perhaps its true electric fields cannot exist inside of conductors.Maybe the electric fields, and hence the current flow exists only on the surface of the conductors. We can test for this. If the electrons were flowing only on the surface, then one would expect the resistance of a section of wire to depend on the circumference of the wire Group Exercise: Discuss how the resistance of a wire would be expected to depend on the size of the wire for the two scenarios (current on surface, current inside of wire).Explanation / Answer
1.Current on surface.
In this case the current would be proportional to the circumference of wire and more specifically the radius of the wire.The reason being that more the radius, more the surface area of wire which will provide increased space for flow of current.Hence current increase and resistance decreases as a consequence of ohms law.So, we can infer that resistance in this scenario will be inversely proportional to radius of wire.
2.Current in wire
In this case current through wire will be proportional to cross sectional area of wire.More specifically current will be proportional to square of radius.Again increased cross sectional area provides more space for current to flow and hence current increases.Now by ohms law, resistance will be inversely proportional to square of radius.
We can sum up above discussion by stating that effect of radius of wire on resistance will be more pronounced in case of current flow through wire than in case of flow on surface.