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Edexcel A2 Physics. Electromagnetic Induction. Please Help Watch

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    This is probably a pretty stupid question but I was wondering if you could help explain it. Say for example you have a magnet turning in a magnetic field at a constant rate. Why is it that an alternating current is produced? I'd have thought that if it is turning at a constant rate the rate of change of flux linkage would be constant so the result would be a DC current flowing. Why isn't this the case?
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    I am wondering if you mean coil rather than magnet?

    If we are talking about a coil rotating in a field, then when the coil is vertical and the field lines are going horizontal, then the conductor is not cutting through the field lines so zero current. As the coil turns into the horizontal position, the conductor now cuts through the field lines at right angles, therefore maximum current.
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    What's the definition of a current? how is it produced? this should suffice.
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    (Original post by eswnl)
    I am wondering if you mean coil rather than magnet?

    If we are talking about a coil rotating in a field, then when the coil is vertical and the field lines are going horizontal, then the conductor is not cutting through the field lines so zero current. As the coil turns into the horizontal position, the conductor now cuts through the field lines at right angles, therefore maximum current.
    I did mean coil, I do appologise I was quite tired when I was writing this.
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    As the rotating coil passes the north pole of a magnet a voltage is produced in a sinusoidal form which reverses as the coil passes the south pole of a magnet. Its mainly do to with the magnets polarity and the coil passing through each polarity, while the magnet is parallel to the coil no emf is induced as the electric and magnetic field lines do not cut so no current is gained. When the planes are perpendicular to the magnet an emf is induced, this is both in north and south poles which affects the direction of the current and voltage.

    Hope this helps im also studying for the same exam.
 
 
 
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