ENSC 220
ELECTRIC CIRCUITS I

Puzzle #7: Magic box


Contributed by Professor Yannis Tsividis

You go to the lab, and connect a battery across the terminals of a black box. Then, using the instruments on the bench, you measure the following:

  • Voltage across the terminals: 1 V.
  • Current entering the box: 2 A.
  • Power dissipation of the box (measured by a watt meter): 0 W.
    What is in the box?
    Last modified: Fri Oct 23 17:28:40 PDT 1998.