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? asked in Science & MathematicsPhysics · 9 years ago

Does DC current spark? If not, why?

4 Answers

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  • Maxx
    Lv 7
    9 years ago
    Favorite Answer

    Have you ever seen lighting? That's DC sparking.

    Electricity sparks (arcs) at 20,000 volt per inch no matter if its AC or DC.

    Usually DC sources are low voltage like batteries and such, so you don't associate DC with sparking, but it will and does. Static electricity is DC also.

    In fact the only reason AC current exist is because it's voltage can be increased by transformers so it can be transmitted over power lines for long distances.

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  • Steve
    Lv 7
    9 years ago

    Yes, and it sparks much more aggressively than AC.

    Reason:

    When a switch carrying DC is opened, the current being interrupted is always equal to the current flowing in the circuit. When interrupting an AC current, the current varies with time, and, on average, is less than the peak current.

    For this reason, a given switch normally has 2 current ratings; one for AC current, and a lower one for DC current.

    Source(s): Experience
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  • 9 years ago

    Any time there is a large enough electric field through the air (caused by a large enough voltage across the air), you will get a spark as the air is ionized to a plasma, and conducting electric current better than it did as a gas.

    It doesn't matter if that voltage is AC or DC.

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  • Anonymous
    9 years ago

    A DC spark is uni-directional and therefore hotter than an AC spark.

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