Electric Current in a Thin Conductor Wire

This interactive simulation models the motion of free electrons in a conductor and illustrates their drift under the influence of an applied voltage with adjustable temperature.

The model is a highly simplified representation!

• Electrons are treated as classical particles moving with random velocities, similar to a gas of particles. Their motion is influenced by both collisions with atoms in the lattice and by external forces via the applied voltage.
• The conductor is represented by a metallic lattice (a grid of atoms), where the electrons randomly scatter when they collide with the atoms.
• The voltage applied to the system causes the electrons to accelerate, simulating an electric current through the wire. As the voltage is increased, more electrons drift toward one end per unit of time, increasing the electric current.
• By increasing the temperature the lattice atoms get more energy and jitter, which affects the motion of the electrons reducing their drift velocity.

The model of free electrons (e. g. Drude model, en.wikipedia.org) is based on classical mechanics rather than quantum physics (like the Fermi gas model, cf. en.wikipedia.org). A weak Coulomb interaction was added to prevent electrons from clustering at high temperatures. Note: Real electrons have a high thermal speed (~10⁶ m/s at 300 K), whereas the drift velocity is much slower (~0.1 mm/s).

The application is inspired by a very old Java applet of the “Europaschule” (Goethe-Gymnasium Ibbenbüren), which was mirrored on LEIFI for some time but is no longer available.