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Electromagnetism and power requirements

  1. Jun 8, 2016 #1
    Can anyone please help I want to calculate the power required to make a electromagnet of strength 1 tesla and length 600km.
    And how much energy a train consume in travelling per km with speed of 112km/h
  2. jcsd
  3. Jun 8, 2016 #2


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    Hi there
    welcome to PF :smile:

    cant help with the first part

    would need to know more info, eg ....
    weight of the train, with passengers etc ... since that is going to vary, so is your power requirements
    there will be friction to take into account

  4. Jun 8, 2016 #3


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    Strictly speaking, power is the rate of energy flow. If you build the magnet very slowly it will require little power, but it will take a very long time.

    The energy needed, (equivalent to a monetary cost), will depend on technology. A superconducting film and cooling system may be more economic than thick conductive bars.

    The cost of turning the DC current to the electromagnet on will be high, because eddy currents will be induced in nearby conductors. How will you minimise the leakage flux yet still benefit from the magnetic field ?
  5. Jun 8, 2016 #4
    In principal no power is required to maintain an electromagnet.

    In practice, power would be required to overcome losses, or to maintain cryogenic temperatures if it is a superconducting electromagnet.

    Edit: Baluncore, looks like we were both typing at the same time.:smile:
  6. Jun 8, 2016 #5
    So I am trying to build a train model with a 1 tesla electromagnet on both side of train producing a field between train and if train is 600km with is average length of a train and running at 112km/h then it would produce enough power to run the train and magnetise the electromagnet.
    The power can be saved with energizing only section in which train is present as just like in magnetic levitation train.
    However initial priming is necessary with diesel engine
  7. Jun 8, 2016 #6
    Average passenger train efficiency I just received from the inquiry of railway department of India
  8. Jun 8, 2016 #7


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    What other sources of energy are being used ?
    If there are no other energy sources, then either you are modelling an inefficient diesel, or you are dreaming of an "over-unity" "perpetual motion machine".
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