Electromagnetic question!

[magnetman]

Hi everyone,

I am most likely the least scientifically minded person to ever have visited these forums! I'm here with a question that I hope someone more scientifically minded can answer for me.

If a pair of plastic coated axial neodymium magnets are installed either side of a sheet of alloy, will the electromagnetic field from the magnets cause electrolysis on the alloy sheet? The alloy sheet will often in contact with salt water.

Thanks in advance for any answers or information on this.

[Strange]

!

Moderator Note

Moved to Physics as this is a straightforward question. 

 

[Danijel Gorupec]

If the system is stationary, then no. If the alloy sheet moves relative to magnets, then still probably no. (Any voltage difference that you might achieve with this simple settings seems unlikely to reach some electrolysis threshold -  although my knowledge about electrolysis is low.)

[magnetman]

2 hours ago, Danijel Gorupec said:

If the system is stationary, then no. If the alloy sheet moves relative to magnets, then still probably no. (Any voltage difference that you might achieve with this simple settings seems unlikely to reach some electrolysis threshold -  although my knowledge about electrolysis is low.)

Brilliant! Thanks very much for your reply

[magnetman]

On 11/18/2019 at 8:06 PM, Danijel Gorupec said:

If the system is stationary, then no. If the alloy sheet moves relative to magnets, then still probably no. (Any voltage difference that you might achieve with this simple settings seems unlikely to reach some electrolysis threshold -  although my knowledge about electrolysis is low.)

I've been told that If a conductor (the salt water) flows through magnetic field, this can also set up electromotive forces... causing anodic corrosion.

Does this make sense or is it nonsense!? Apologies for my lack of understanding.

[Danijel Gorupec]

2 hours ago, magnetman said:

I've been told that If a conductor (the salt water) flows through magnetic field, this can also set up electromotive forces... causing anodic corrosion.

Does this make sense or is it nonsense!? Apologies for my lack of understanding.

It might make sense... If the fluid velocity at about 10 meters per second (22mph) and if the magnetic field is 1 tesla (quite strong) then you can have 0.1V per each centimeter of the width of the fluid flow. So I guess if the flow and the magnetic field is wide enough (20-30 centimeters or more) and if other conditions are just right, you can have some electrochemical effect.

I however am not very good at chemistry and maybe someone else wants to comment how much voltage is actually needed to start electrolysis (or whatever).

[magnetman]

On 11/20/2019 at 1:43 AM, Danijel Gorupec said:

maybe someone else wants to comment how much voltage is actually needed to start electrolysis (or whatever).

Any takers?? Would love to get to the bottom of this

[swansont]

The minimum voltage for electrolysis of water is ~1.25 volts (it will not happen with less), but in practical terms you need more to overcome resistance.

https://en.wikipedia.org/wiki/Electrolysis_of_water