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A Simple Question

  1. Aug 31, 2003 #1
    I have a questiaon which you can easily answer I think. If you do I'll be :smile: :smile: :smile: because I'm thinking about it for roughly 2 days.

    Think we have a generator with an electric bulb connected to it. The PE of the water (from the dam) turns the turbine and our bulb gives light. Now we remove the ampoule and still the turbine is turning but where is the E from the generator going?

    In other words is it harder to turn the pivot when a bulb is connected?[?]
  2. jcsd
  3. Aug 31, 2003 #2


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    Science Advisor

    Yes, without the bulb the generator turns more easily. The bulb puts a "load" on the generator, making it resist turning. With this load removed, the generator is turning against its own friction, and whatever energy it is making is being used mostly to make the bearings hot and produce those high-pitched soundwaves a generator makes when it spins too freely. But mostly, the energy the bulb is no longer being taken from the moving water. The water flowing through the dam now has more energy because the bulb is off.
  4. Aug 31, 2003 #3
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