These 2 properties also make certain aluminum alloys the ideal material for the disc of a KWHR meter or eddy current brake. These aluminum alloys also make for excellent electromagnetic shields hence the better flexible coaxial cables cable TV, closed circuit television have one or more layer of aluminum ally foil in addition to copper braid - the aluminum foil both closes the holes in the copper braid and confines small magnetic fields to the interior or exterior of the cable.
Copper braiding only shields of coaxial cables can be used to make a shielded air core radio frequency transformer but the copper plus aluminum foil cables cannot be used for this.
The copper plus aluminum foil cables cannot be used for a radio transmitter above a few watts. This application requires plain copper braid coaxial cable or aluminum sheathed "hardline" coaxial cable. Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group.
Create a free Team What is Teams? Learn more. Puzzled by magnetized aluminum! Ask Question. Asked 8 years, 8 months ago. Active 7 years, 4 months ago. Viewed 8k times. Improve this question. Maesumi Maesumi 2 2 silver badges 15 15 bronze badges. Add a comment. Active Oldest Votes. Improve this answer. John Rennie John Rennie k gold badges silver badges bronze badges.
Michael R. They both just sort of site there. Yes, it does. Aluminum Pipes and Magnets To really see this in action you can drop a strong magnet down an aluminum pipe.
As the magnet moves down the pipe it creates small electrical currents in walls of the pipe. These electrical currents repel the magnet and cause it to fall slower. With larger pipes and magnets the effect is more dramatic.
It's difficult to find really thick pipes but thinner pipes will work. You need to make sure you have really strong magnets neodymium rare earth magnets and a few feet of aluminum or copper pipe to see the effect.
The magnet should be fairly close to the size of the pipe for the best effect. To see this taken to an extreme watch what happens when a tube of aluminum foil is put near the very strong magnetic field generated by a MRI machine the M in MRI stands for Magnetic.
Note how much fun the guy is having. If you move the magnet over the can you can actually cause the can to rock back and forth and eventually role.
If you are concerned and as a thoughtful scientist you should be that air is causing the can to move you could try it with another object like an eraser or piece of wood. If you do you'll find the can doesn't move. Aluminium, on the other hand, is quite different.
While it's not far behind in terms of conductivity, it is not attracted to magnets as iron is. To understand the relationship between metals and magnets, you have to look at certain elements which foster this relationship carefully. It's referred to as a paramagnetic material along with other metals like Magnesium and Lithium.
A sheet of aluminium might not be attracted to a magnet, but, you can observe hues of magnetism when you drop a strong, high-quality magnet down a thick aluminium pipe. The hues are characterised by a notable slow fall of the magnet. This is caused by the magnetic repelling, the magnetic fields created as the magnet passes the aluminium dipoles.
Paramagnetic materials have a composition similar to ferromagnetic materials which are readily attracted to a physical magnet. Paramagnetic materials have unpaired electrons in their partially filled energy orbitals.
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