electromagnet

Assuming the penny is ferromagnetic you might be able to use DC to drive the electromagnet (i.e.

One possible reason for that is that a speaker is essentially just a paper cone with an electromagnet on it.

For the cans they use electromagnet while the trash is on the belt that makes the cans jump farther than the garbage.

So in this case the photons travel from the electromagnet to the static magnet, and they carry away some moment and energy, so the moment is conserved locally.

Any real counter-forensics device should be at least as good as the door electromagnet in Cryptonomicon.

The images are of electrons scattered from hydrogen atoms, directed onto a plate by an electromagnet.

In practice, this looks like an electromagnet that's held just over the rail.

I would wrap an electromagnet around the magnet in the tube, then turn on current to create a field in the opposite direction.

Infrastructure would then be a small landing pad with an electromagnet to hold the buoyant blimp up so the fans don't have to continue to run while charging.

Idea is that single assembly combines this for small braking strengths and friction braking for complete stop (the electromagnet is on springs and can come into complete contact with rail, which is used as equivalent of parking brake).

Hm, I assumed it was a permanent magnet, not an electromagnet.

There is nothing 'special' about it, it's just the same principle as magnetizing a needle with an electromagnet only you move the needle as you go and you alternate the current in the electromagnet with the sound you wish to record.

With electromagnet and iron rail the same effect is used for almost an century on streetcars under the name "electrodynamic brake".

No, the needle will not become an "electromagnet," once it's outside the coil.

The "Hover engine" is basically just a big electromagnet.

The satellite (I picture it as a donut, with the projectile aimed at the center) uses an electromagnet to "fix" the launch vehicle's orbit.