Eduard-Job-Foundation for Thermo- and Matterdynamics

Experiment 3.3: Expansion of a Wire Caused by Electric Current


First, the current is slowly increased. Then, the current is decreased again.

The weight sinks down slowly with increasing current. At higher current, the wire also begins to glow. If the current is decreased the weight moves upwards again. ??

Entropy is generated by the electric current. As main effect of the increase in entropy the wire becomes warmer and finally begins to glow. But the increasing entropy also causes a side effect: The wire lengthens noticeably. If the electric current is decreased again, also the entropy generated in the wire decreases; the wire gradually cools down and shrinks again.

Video (mpg4, 1:04)