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EM induction problem

  1. Aug 2, 2005 #1
    I have a problem:

    In EM induction, when we increase the number of turns in a coil, the induced e.m.f will increase, thus the current. Why does the current also increase?

    But in operating a transformer, when the voltage of the output current increases, the current decreases. How come? The e.m.f. of the output current becomes larger, isn't it the same case as above that the current would also be increased?

    In motional induction, when the induced e.m.f. increases, the current increases. Why does only the e.m.f increase in mutual induction?
    Last edited: Aug 2, 2005
  2. jcsd
  3. Aug 2, 2005 #2
    The current in a load would increase with increasing EMF, as in a resistor
    connect to the transformer.

    It's not the current but the transformers's current handling ability
    for a fixed power which changes.

    An ideal transformer could deliver inifinite current into a short.

    A real transformer can only handle a certain number of watts, so the
    max current permitted (before metling the wires) is fixed by the design.
    Last edited: Aug 2, 2005
  4. Aug 2, 2005 #3
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