Most recent answer: 09/11/2013
- Chris C (age 31)
Broomfield, CO, USA
The key question here is whether the ferrofluid keeps its magnetization long enough to induce eddy currents in the coil. I don't think it will.
The magnetic particles will lose their alignment by simple thermal rotational diffusion. In other words, just plain thermal energy makes each particle randomly turn. The characteristic times to keep orientation depend on the particle diameter, the fluid viscosity, and the temperature. () Just grabbing some numbers from Wikipedia, it looks like a typical ferrofluid particle diameter is about 10nm. () If the fluid has viscosity similar to water, the characteristic diffusion time will be of order 10-6 s.
(published on 09/11/2013)