Thread: An expriment makes me confused!

Take a hollow soft plastic pipes one meter long, outer diameter 8 mm, internal diameter 6 mm, fill it up with salt water.
Take an iron shaft with 20 mm diameter.
Make the pipe rolled on the iron shaft as a spiral pipe.
Insert electrodes in plastic pipe ends , connect the two electrodes in 6 volt dc power between anode and cathode.
Turn on the switch, let the current run through , the both ends of the shaft cannot absorb any small nails!
Maybe my expriment is not accurate?
Perhaps Osterad only said out a half truth: the current in the solid metal conductor has magnetic effect,and the current runs in an electrolyte solution does not produce any magnetic effect at all.
Who is interested in it and would like to verify it or explain it?

Have you measured the current through the solution?
Have you used something more sensitive, such as a good compass, to test for a magnetic field at the ends of the iron rod?

1;Yes,I did do!
I repeated many times . 2 A, 4A,
2;Because the shaft is made of iron I can't use compass neaeby.

Originally Posted by Emdrive

1;Yes,I did do!
I repeated many times . 2 A, 4A,

Have you tried the same experiment using the same length of copper wire and the same current?

2;Because the shaft is made of iron I can't use compass neaeby.

Can you explain what you mean by that? I would have thought a compass was the obvious simple instrument to use to detect a small magnetic field.

1,When use copper wire, only 1 volt battery ,more than 5 small nails were absorbed.
2,Compass will be disturbed by the iron shaft nearby.

Originally Posted by Emdrive

1,When use copper wire, only 1 volt battery ,more than 5 small nails were absorbed.

What was the current?

2,Compass will be disturbed by the iron shaft nearby.

Only if it is magnetic. You are trying to detect magnetism (or at least a change in magnetism) so it should be the perfect instrument.

1,Less than 1A.
2,Instrument? Maybe, but I think this can be used in power field.

Emdrive: apologies if I've misread your question, but it sounds like you're performing electrolysis. See wikipedia and the section that says this:

"Each electrode attracts ions that are of the opposite charge. Positively charged ions (cations) move towards the electron-providing (negative) cathode, whereas negatively charged ions (anions) move towards the positive anode".

In a current-carrying copper wire only the negative particles, the electrons move. The positive particles, the protons, stay put. Then their electromagnetic fields don't quite mask one another, and the result is what we call a magnetic field. Note though that the only field present is the electromagnetic field, see wikipedia and this paragraph:

"In the past, electrically charged objects were thought to produce two different, unrelated types of field associated with their charge property. An electric field is produced when the charge is stationary with respect to an observer measuring the properties of the charge, and a magnetic field (as well as an electric field) is produced when the charge moves (creating an electric current) with respect to this observer. Over time, it was realized that the electric and magnetic fields are better thought of as two parts of a greater whole — the electromagnetic field".

Thank you for your patience and kindness.
I am sure it's a electrolysis process.
Accidental I watched a video in the net. Someone lets current run through salt water and places a magnet hanging above the water.
The magnet begins to swing. I tell him he maybe get a good way to drive machine but he refused to admit it.
When I repeat the expriment I think it's worthy to check the magnetic effect of current in electrolyte solution.
But the phenomenon surprised me .

Do you have a link to that video? There's some interesting videos on the web wherein electrolysis demonstrates the vorticial nature of the electromagnetic field.