• The turn on time of 2 identical bulbs in separate circuits is compared. 1 bulb is in series with an inductor, but the current is the same in each circuit.
  • When the switch is closed, the bulb in series with the inductor turns on more slowly.
  • The effect is most pronounced when both bulbs are cold.






        (use 2 - 12 V, 50 W bulbs)
        (use ammeters to match current in both circuits, bulbs should glow with equal brightness)


  • Version 2
  • 2 identical bulbs are connected in parallel, but 1 bulb has an inductor in series.
  • When the switch is closed, the bulb in series with the coil turns on more slowly.
  • Limit ON time to 15 seconds to keep the coil from overheating.

        (use 2 - 12 V, 15 W bulbs and green 16 ohm coil)
        (match the current in both circuits, bulbs should glow with equal brightness)

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