How does the govt/military change the configuration of the large magnets they use for rail guns ?
78592
Magnetism is simply the movement of charge.  If you take a coiled wire, and put an electrical current through it, you will in effect get a magnet.
1074897
absolutely, the military is working on one right now for there new electric battleship (in 2011). However, a railgun doesn't use heat to accelerate a projectile and the heat is just a sideeffect. a rail gun uses two electricaly charged superconductive rails, hence the name, to creat a super strong magnetic field around the armerture to fire the slug. The slug is made from DU(depleted uranium) or tungragen so it woudn't turn into a beam. Real railguns have the distructive energy as a small nuke without the radiation and complex dilivery system. a cheap 40 kilogram (about 75 pounds) can vaporize a target 600 miles away in a few minutes. the barral volocity is many times that of a regular gun and can be as high as Mach 9
856860
You would need to have the magnet moving, and the power it would take to make it move would be more than any advantage you get out of it. Laws of Thermodynamics.
104827
An electromagnet , it is temporary magnet.without the electrocity, it is not a magnet.
905389
Bound's hubby here:\n\nI have a Derek Martin trigger in my AR match rifle (I am not suggesting that you get one). The way he, and the Marine armorers that checked/adjusted my installation adjusted the trigger pull was to bend the "legs" of the trigger spring ever so slightly, not the hammer spring!\n\nGood luck!
930419
1. Increase the speed of the rotor\n2. Modify the generator by increasing the number of windings on the rotor.\n3. Modify the generator by using stronger fixed magnets.
128833
Three types of magnets:\n\n-Ferromagnets: Magnets which retain a magnetic field after having been magnetised in a magnetic field.\n\n-Paramagnets: Magnets that only exert a magnetic field when they're in another magnetic field.  They support the magnetic field they're in.  Usually their fields are quite weak compared to the external fields.\n\n-Dimagnets: Magnets that exert a magnetic field when they're in another magnetic field but opposing the field.  (Think: *DI*ametrically opposite).  Again, field intensity created by these magnets typically is very small compared to the external field.\n\nAdditionally, many dimagnetic and paramagnetic materials may become ferromagnetic if they are sufficiently cooled.\n\nPermanent magnets are most often ferromagnetic and will retain their magnetism for a long time even in the absense of a magnetic field.  Over time, however, thermal effects will slowly decrease field intensity, but that takes a long time for permanent magnets.
148650
You can make a magnet and stamp it as you wish. You have the freedom. Try marking dakshin and uttar. But it will not be a standard magnet. Only you will be using and understanding it.
268504
I'm not sure anyone really "know" but there are many teltail clues.  Not all materials are magnetic except perhaps under very powerful magnetic fluxes (MRI's?) but all atoms of materials do have one or more electrons orbiting their nuclii.  We know that electrons can be directed by magnetic flux, perhaps in a TV picture tube, etc.  Therefore, the number and arrangements of electrons of the atoms differ and some create magnetic properties (dipoles or two different poles).  If an iron bar is heated to a high temperature all the iron atoms in the bar are permitted to spin around willy-nilly.  If the bar is then cooled while exposed to a strong magnetic flux (electromagnet?) all its dipoles will align uniformly with the external flux like the needles of compasses aligned with the earth's flux.  When cool, the magnet exhibits the combined strength of all the dipoles that were previously working against each other.  We know that atoms repel each other because of their electrons (and even their nuclii must be forced together to fuse because of protons) like basketballs with ballbearings at their centers, where the skins are made of rapidly orbitting electrons.  Whereas the basketballs would repel each other in any given positions, actual atoms in iron crystals repel directionally and they which can attract or repel a free electron.  The magnet has collectively directed their combined force.  If each dipole has a North and South pole, we would expect the entire magnet to also have a North and South pole, and for like poles to repel, just as in the individual dipoles.  Hope that helps a little.
22759
A permanent magnet uses ferromagnetism, which - in laymen's terms - is caused by a huge number small electromagnets in the form of unpaired electrons orbiting an atom. In permanent magnets, these elementary magnets are mostly oriented the same way.\n\nBy heating the permanent magnet, the atoms are excited into vibrations which may change the orientation of the elementary magnets. Rather than acting in concert, the magnets become randomly aligned if the permanent magnet is heated long enough.\n\n\nStars and planets generate magnetic fields in a different way.
1097908
Iron, cobalt and nickel can be magnetic. They can be made to have polarity. Poles that are alike repel and poles which are not alike attract. A magnet will attract all of them if they are not polarized. If they are polarized, a magnet will attract or repel according to the polarity.\n;-D
574031
There are two confinement methods to confine high temperature plasma. One way is by applying magnetic fields so that the plasma particles are forced to follow a helical path around the field lines.To increase the confinement the device is usually made in a toroidal shape so that the particle remain attached to the same field line for a lnger time thus increasing the confinement. This method is known as Magnetic confinement and is frquently used in fusion devices and other plasma devices.\n     Another less frequently used method is Inertial confinement fusion where intense lasers are used to confine the plasma by employing the radiation pressure of the laser radiation.\n\nThough in both the methods there are few unresolved issues like instabilities, anomalous transport etc. Research is going on to find a solution of the problems.
1090476
Iron (like steel and certain alloys) contains atomic magnets or dipoles which can line up their 'magnetic axes' in a preferred direction.  In the magnetized state, all the magnetic axes will point in one specific direction, by which the iron filling will show polarity and hence be a magnet itself.\nWhen you heat the iron fillings, the high temperature makes the atoms to vibrate with increasing energy and this disturbs the dipoles and so the resultant magnetic axes point in their 'preferred' random directions, which keep changing due to the extra energy. If the iron fillings were magnetized before heating, all the magnetism would be lost. Magnetizing them after heating will not align the vigorously vibrating atomic magnets and rapidly changing magnetic axes.
591429
It's a very clever device actually.  You have a circular armature that spins in the middle sorrounded by circular coils.  Both of these parts have conducting coils of wire in them. So you have a series of electromagnets shaped around each other.  \n\nThere are also switches that move the current around the particular sections.  When you plug the motor in, the magnetic field can be manipulated so that it moves around in a circular path.  The magnets in the armature are drawn to it and move toward it.  But as soon as it gets close, it is switched off and the next one along the circle is turned on.  Again, pretty tricky to make, but we've figured it out - great device.
578855
When a current passes thru spring a magnetic feid is produced since the current pases in same direction in all coils of spring the magnetic feild will have same direction i all coils. So the N and S poles of adjascent magnets (coils) come near and thus attract. This causes the epring to reduce its length
591035
Ferromags are substances that are strongly attracted by a magnetic substance. Some ferromagnetic  metals are iron, cobalt, nickel, gadolinium and dysprosium. To generate electricity from ferromags, take two iron sheets 5 cm wide. rub both of them using a bar magnet only in one direction for about 10 minutes. This will impart magnetic properties to d iron sheet. Then u arrange the sheets in such a way that u feel d force of attraction between the sheets. take a copper wire. make a loop out of it. rotate d loop in d space between d sheets with a constant frequency. Voila electricity generated at d ends of d loop
641079
I believe that to reverse the polarity of and electromagnet you need to reverse the eletric current becarse the move ment of eletrons makes magnets