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Two sides of a same coin. But how?

  1. Jul 28, 2005 #1
    Two sides of a same coin. But how??

    You are perhaps confused by the title, isn't it?
    Well let me tell you what the question is.

    Electricity and Magnetism are said to be "two sides of a same coin". But can anybody help me understand the actual relation between electric and magnetic fields and that how does electromagnetic induction works?

    In short, I want to know how were the two phenomena- Electricity and Magnetism, unified into a single theory called 'ELECTROMAGNETISM'
  2. jcsd
  3. Jul 28, 2005 #2


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    Staff Emeritus
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    If I point to you the Maxwell Equations, would that be sufficient?

  4. Jul 28, 2005 #3
    Yes, Maxwell's equations will give you the answer. Unfortunately, you have to be able to UNDERSTAND Maxwell's equations to appreciate that. Short answer (in English) is that a changing electric field has an associated magnetic field and a changing magnetic field induces an electric field.
  5. Jul 28, 2005 #4

    Doc Al

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    Staff: Mentor

    Add to that the insights of special relativity and you'll see that what one observer sees as an electric field will appear as a magnetic field to a moving observer. In relativity, electric and magnetic fields are interwoven.
  6. Jul 28, 2005 #5

    Magnetism is what you see when the electric field is moving compared to you.
    Induction is the other side of that coin- When magnetism is moving compared
    to you, you also see an electric field.
  7. Jul 28, 2005 #6
    The simplest practical explanation: A wire with an electrical current through it produces a magnetic field in the surrounding space.

    It is worth mentioning maxwell's equations have that two sides of the same coin aspect, as well as predicting that light itself is a wave of electric and magnetic fields.

    The ultimate unification comes from Einstein's Special Relativity, which shows how electric and magnetic fields are the same thing seen from different points of view.
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