When a wire is amde smaller the resistance increase what happen to the electric current?

If a circuit existed where a wire could be made smaller AS the current from a defined source was applied to a defined user then in terms of amperage there would be little change in that parameter. In terms of the Power dissipated as heat through the electrical resistance of the wire then the wire would exhibit a marked increase in the heat expended (Power -watts= amperage- I x voltage -E) . With this in mind and using the same formula as noted the increase in P can only be attributed to an increase in E .To maintain the amperage -I. In short the smaller the wire the greater the voltage must be to maintain a set unit of amperage. In real world projects however the user raises wire size and does not modify voltage to maintain the amperage capacity. This is covered by the idea of calculation of voltage drop in a conductor based on its cross sectional area. From your question let me remind you that amperage is a function of usage and although stated on many devices does not exist until a circuit is closed ..Have a good one Edesigner.