Yes, submarines can pump seawater magnetically. There are some great YouTube videos on this.

 

I am aware of magnetic coupled pumps. But not true hydro-magnetic pumps.

So if I fill a hula hoop full of salt water........wrap large wire coil around a section.....the salt water will flow on charge and discharge of the coil,.....back and forth around the hoop?

 

To get motion around the tube the electrical current would have to be transverse to the tube bore.

 

The coil current is transverse of hoop bore. Right?

Let's wind wire completely around the hoop. Like a toroid coil. Isn't the current always transverse to the bore?

 

Could we add salt to water, then use a magnetic field to pump it?

'Apparently' this can be done well using 'free energy'.

 

I guess I'll never know. I thought I had some tubing......but it's gone.

This new high tech stuff is fascinating.

 

Isn't the current always transverse to the bore?

I was referring to the electric current conducted through the liquid inside the bore of the hoop; not the current through the wire wrapped round the hoop.

 

I have to ask: why the water-filled tube rather than a simple wire?

magnetic relative permeability of water is comparable to that of copper
water =0.999992
copper =0.999994
https://en.wikipedia.org/wiki/Permeability_(electromagnetism)
and high specific heat of water keeps temperature low , hence impedance does not get too high due to high currrent

 

and high specific heat of water keeps temperature low , hence impedance does not get too high due to high currrent

But the electrical resistance of of the saline filled tube will be much higher than an equivalent length of copper wire so the heat generated in the tube will be much higher.

 

ok....so does that mean....that if everything being equal (voltage and current and resistance of wire coil and saline coil equal.).......if I change out a wire coil for a saline coil......we get a stronger H field and a larger voltage drop?

magnetic field (at end of solenoid)= u*i*n*0.5 (u=permeability n= terns per unit length)
(itll be a little less 10cm away but not much since radius to length ratio is small)

Does a tube of saline have inductance?

yeah, self inductance (solenoid)= pi* u* (n^2) * (r^2) / l (l= length of solenoid n= total turns r= radius of solenoid u= permeability)

 

That's because it's somewhat impractical. The salt water at 0.1M will have a conductivity of only about 10µS/cm. Compare to copper wire at 6x10^5 S/cm. Note S versus µS.

It'll take a high voltage to drive enough current to get much of a field. The high voltage will cause electrolysis, so I'm not sure this has any chance at all.

But the electrical resistance of of the saline filled tube will be much higher than an equivalent length of copper wire so the heat generated in the tube will be much higher.

that can be fixed by increasing molarity

 

The conductivity of saturated saline is about 25 S/m while copper is about 60 million S/m.

 

You can't fix the electrolysis issue, which will limit your voltage. A limited voltage across a large resistance means low current and low magnetic field. You might be able to deflect a compass needle but I wouldn't hope for much more.

 

You can't fix the electrolysis issue, which will limit your voltage. A limited voltage across a large resistance means low current and low magnetic field. You might be able to deflect a compass needle but I wouldn't hope for much more.

if saline is replaced by conc H2SO4 soln and plastic tubing is used will it help?

 

The maximum conductivity of sulphuric acid is at a concentration of around 30% and is around 83S/m so not much more conductive than saline and still a very long way from copper.

 

The maximum conductivity of sulphuric acid is at a concentration of around 30% and is around 83S/m so not much more conductive than saline and still a very long way from copper.

ok i give up

 

Liquid mercury or gallium would both work great, if your goal was to make a liquid coil. If you insist on an aqueous coil, your options are limited.

 

Liquid mercury or gallium would both work great, if your goal was to make a liquid coil. If you insist on an aqueous coil, your options are limited.

what if mu-metal is used for the core( replacing soft iron)? will magnetic field be large enough to attract the iron nails?
https://en.wikipedia.org/wiki/Mu-metal
http://custommagneticshielding.magneticshield.com/viewitems/mumetal-sheet-and-foil/mumetal-foil