Climbing Arc

(Amy Murphy)
  • Description: The climbing arc consists of two electrodes. The electrodes are spaced close together at the bottom and they become farther apart at the top, giving it a "v" shape.  The climbing arc has also been called a "Jacob's Ladder" and is often seen in old sci-fi movies.  When high voltage is applied to one of the electrodes it creates an arc or "spark" between the two electrodes.    As the air inside the tube becomes heated by the electrodes the arc will begin to travel upwards, because the air resistance is lowered.  Eventually the electrodes become too far apart and there isn't enough voltage for the arc to continue.
  • Photographs:

  • Principles: air conductivity, Paschen's LawV=\frac{a(pd)}{\ln (pd)+b}\  
            Could also be used to teach Earth sciences
  • Video:

Climbing Arc "Jacob's Ladder"