What is the current level of JSA?

Current through a resistor at atomic level & voltage drop - what's going on?

• I have trouble understanding electricity at the atomic level. What happens when current goes through a resistor? Let's say that the electrons of the conductor at the border between the conductor and the resistor "bump" against the electrons of the resistor - what next? How is the energy of electrons affected? Why does the voltage "drop"? No water analogies or circuit level analysis, please. It would be nice if someone could answer in the most fundamental level possible.

• Answer:

  The electrons carry energy. Electric current means that they are in motion, so it is kinetic energy. The amount of energy per electron is called voltage. When they bump into the atoms of the resistor they lose some kinetic energy to them. This causes the atoms to vibrate faster, heating up the resistor. Voltage drop = a decrease in kinetic energy of the electrons The amount of kinetic energy lost to the resistor is determined by the following factors: the length of the resistor (the longer, the more energy lost), the cross section area (the thinner, the more energy lost since there is less space available and more "bumping" occur) and, the type of material (silver and copper facilitate the flow of electrons, glass and plastics hinder it).