How did early scientists know if a current was changing direction? (AC vs. DC)

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How did Faraday, Ampere and Hippolyte Pixii know that electricity 'traveled' at all? Let alone in a certain direction? And that it was reversing direction with certain early generators?






electromagnetism electric-current history







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    I imagine that if you put a compass next to a wire, the compass needle feels the magnetic field from the wire. If the field is switching direction, the needle should wiggle...
    – DanielSank
    2 hours ago










  • Perhaps this is a question better suited to History of Science and Mathematics SE?
    – Chair
    1 hour ago














up vote
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How did Faraday, Ampere and Hippolyte Pixii know that electricity 'traveled' at all? Let alone in a certain direction? And that it was reversing direction with certain early generators?






electromagnetism electric-current history







share|cite|improve this question



















  • 2




    I imagine that if you put a compass next to a wire, the compass needle feels the magnetic field from the wire. If the field is switching direction, the needle should wiggle...
    – DanielSank
    2 hours ago










  • Perhaps this is a question better suited to History of Science and Mathematics SE?
    – Chair
    1 hour ago












up vote
4
down vote

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up vote
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How did Faraday, Ampere and Hippolyte Pixii know that electricity 'traveled' at all? Let alone in a certain direction? And that it was reversing direction with certain early generators?






electromagnetism electric-current history







share|cite|improve this question















How did Faraday, Ampere and Hippolyte Pixii know that electricity 'traveled' at all? Let alone in a certain direction? And that it was reversing direction with certain early generators?






electromagnetism electric-current history




electromagnetism electric-current history






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Aaron Stevens

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Kurt Hikes

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  • 2




    I imagine that if you put a compass next to a wire, the compass needle feels the magnetic field from the wire. If the field is switching direction, the needle should wiggle...
    – DanielSank
    2 hours ago










  • Perhaps this is a question better suited to History of Science and Mathematics SE?
    – Chair
    1 hour ago












  • 2




    I imagine that if you put a compass next to a wire, the compass needle feels the magnetic field from the wire. If the field is switching direction, the needle should wiggle...
    – DanielSank
    2 hours ago










  • Perhaps this is a question better suited to History of Science and Mathematics SE?
    – Chair
    1 hour ago







2




2




I imagine that if you put a compass next to a wire, the compass needle feels the magnetic field from the wire. If the field is switching direction, the needle should wiggle...
– DanielSank
2 hours ago




I imagine that if you put a compass next to a wire, the compass needle feels the magnetic field from the wire. If the field is switching direction, the needle should wiggle...
– DanielSank
2 hours ago












Perhaps this is a question better suited to History of Science and Mathematics SE?
– Chair
1 hour ago




Perhaps this is a question better suited to History of Science and Mathematics SE?
– Chair
1 hour ago










2 Answers
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Daniel Sank is correct; with a magnetized needle on a pivot and a coil of wire you can make a device called a galvanometer with which you can watch current change direction, at least for low frequencies of reversal. The early experimenters could connect galvanometers to their electrochemical experiments and correlate the direction of needle deflection to the direction of charge transport.






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    Well physicists also conducted experiments on Electrochemistry and stuff like Electroplating and where one metal atom 'travels' to another may have made them think about electricity 'travelling'.






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      Daniel Sank is correct; with a magnetized needle on a pivot and a coil of wire you can make a device called a galvanometer with which you can watch current change direction, at least for low frequencies of reversal. The early experimenters could connect galvanometers to their electrochemical experiments and correlate the direction of needle deflection to the direction of charge transport.






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        up vote
        2
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        Daniel Sank is correct; with a magnetized needle on a pivot and a coil of wire you can make a device called a galvanometer with which you can watch current change direction, at least for low frequencies of reversal. The early experimenters could connect galvanometers to their electrochemical experiments and correlate the direction of needle deflection to the direction of charge transport.






        share|cite|improve this answer






















          up vote
          2
          down vote










          up vote
          2
          down vote









          Daniel Sank is correct; with a magnetized needle on a pivot and a coil of wire you can make a device called a galvanometer with which you can watch current change direction, at least for low frequencies of reversal. The early experimenters could connect galvanometers to their electrochemical experiments and correlate the direction of needle deflection to the direction of charge transport.






          share|cite|improve this answer












          Daniel Sank is correct; with a magnetized needle on a pivot and a coil of wire you can make a device called a galvanometer with which you can watch current change direction, at least for low frequencies of reversal. The early experimenters could connect galvanometers to their electrochemical experiments and correlate the direction of needle deflection to the direction of charge transport.







          share|cite|improve this answer












          share|cite|improve this answer



          share|cite|improve this answer










          answered 39 mins ago









          niels nielsen

          11.6k41834




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              Well physicists also conducted experiments on Electrochemistry and stuff like Electroplating and where one metal atom 'travels' to another may have made them think about electricity 'travelling'.






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                up vote
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                Well physicists also conducted experiments on Electrochemistry and stuff like Electroplating and where one metal atom 'travels' to another may have made them think about electricity 'travelling'.






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                  up vote
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                  Well physicists also conducted experiments on Electrochemistry and stuff like Electroplating and where one metal atom 'travels' to another may have made them think about electricity 'travelling'.






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                  Well physicists also conducted experiments on Electrochemistry and stuff like Electroplating and where one metal atom 'travels' to another may have made them think about electricity 'travelling'.







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                  answered 9 mins ago









                  Harshit Joshi

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