1. The electromagnetic rotation of water
Ivan Lomachenkov
The electromagnetic rotation of water
The rotation of water in magnetic and electrical fields demonstrates the effect of a magnetic force on charged particles. It’s a simple equipment.

2. The equipment: • cylindrical glass vessel (about 10-15 cm diameter);
• two electrodes (central and circular electrode);
• magnet (preferably a cylinder);
• source of electricity (about V);
• ampere meter, voltmeter;
4/17/2019
CERN HST2001

3. The physical picture:
Put some salt into the water (either NaCl or CuSO4), about 5-10%. Therefore we have the electrolyte:
H2O + NaCl=>Na+ + Cl-
The positive and negative ions begin to move in the radial direction but the magnetic force acts perpendicular to the ion’s trajectory. Hence the water starts to rotate.
4/17/2019
CERN HST2001

4. The scheme of the facility:
Na+ - B E - + +
magnet
4/17/2019
CERN HST2001

5. Some estimates:
It is not difficult to estimate the radial velocity of the ions of Na. The result is vr~ I/n, where I is the current and n is the concentration of the ions. For a current ~ 0.1 A we have vr~ 10-7m/s.
We can also estimate the circular component of the velocity: v~ nvrB/, where  - the viscosity of the solution. For inductance B~10-2 T and ~10-3kg/(m·s) the result is v ~ 10-2 m/s.
A visible observation confirms this estimation.
4/17/2019
CERN HST2001