when a diamagnetic substance is inserted to a current carrying solenoid the magnetic field is?
363907
For dia magnetic substances the permeabilities are slightly less than unity. Hence the field is hardly affected.\n\nIf a diamagnetic needle is placed in a nonuniform magnetic field it will be repelled.\n\nIn uniform field the needle turns perpendicular to the flux line.\n\nInside a solenoid the magnetic field is uniform. The position of dipoles are such that the external magnetic field is not affected much.
220810
No equations but this may help.... when an electrical signal is travelling along, for example a piece of copper wire, there will be a field generated aroung the cable, similar to that of a magnet (remember at school we were taught about magnetic fields  with a magnet piece of paper and iron filings)\nWhen a second piece of wire is brought in close proximity to the 1st piece then it will cut the field , and a signal will be induced into the second piece of wire.This is called mutual induction. If a signal is now added to the second wire then the induced signal will either add or detract from it dependant on the phase at the time.... this will happen, also within the 1st piece of wire, as a field is now being generated by a signal supplied to the second wire.\nNow, by twisting the pairs together the field generated by the signal in the wire will be changing direction along its length (positive then negative then positive and so on)thus cancelling any induced signals (could be crosstalk in a speach circuit) out
85373
Magnetic force........
933992
the law states that if a wire with length L carries a current i, then a magnetic field is induced...  the magnetic field b (at a point r away) should be induced.... \n\nthe vector notations like dL (hat) and r (hat) are important because the direction of your induced magnetic field is determined using vecor algebra.... you can use the right thumb rule for that too.... the direction of the induced magnetic field  depends on the direction of your current that pass through the wire...\n\nnotice the magnetic field (look at the formula) is a vector quantity since length vector is crossed to the displacement vector....\n(vector cross vector is vector\nand vector dot vector is scalar)
419633
(m)\n\nIn physics, a magnetic field is an entity produced by moving electric charges (electric currents) that exerts a force on other moving charges. (The quantum-mechanical spin of a particle produces magnetic fields and is acted on by them as though it were a current; this accounts for the fields produced by "permanent" ferromagnets.)
270208
Intensity of current and magnetic permeability of the core.
179510
The lines of force produced by the electrons in a magnetic field are like the wake produced by a boat. When that wake encounters another boat it will push it along in the water. Likewise when lines of force in a moving magnetic field encounter electrons it will push them. So the magnetic field produced by current flow in a wire can induce current flow in another wire.
702587
It won't be easy to calculate.  You can easily calculate the strength of the magnetic field of the electromagnet with the current and the number of turns.  But it's harder to know the field strength of the bar magnet, and even harder to calculate the force produced by the interaction between the fields.  Once you got that force, it's easy to compare that to the gravitational force on the mass of the bar magnet.  It's probably easier just to build it and try it.  All you really need is a coil of wire and a current.\n\nOnce you have the apparatus, borrow an instrument to measure the fields.  I'd have more fun with a ball bearing on a circular (non-magnetic) track, timing the current to make the ball move around the track, like a cyclotron.
682407
This is done to link the flux produced in one coil with the other one.Each time the current reverses in the first coil the magnetic flux also reverses which if properly linked with the second coil will induce an emf in the second one as the induced emf will produce a magnetic field which opposes the change in the magnetic field due to the first coil.Iron has a high value of relative magnetic permeability.Thus most of the magnetic flux due to the first coil will pass through it.And if a second coil is wound over it the changing flux will pass through that one too.
781372
"The flux through an element of area perpendicular to the direction of magnetic field is given by the product of the magnetic field density and the area element. More generally, magnetic flux is defined by a scalar product of the magnetic field density and the area element vector. Gauss's law for magnetism, which is one of the four Maxwell's equations, states that the total magnetic flux through a closed surface is zero. This law is a consequence of the empirical observation that magnetic monopoles do not exist or are not measurable."\n\nThis, and much more, including equations, are on Wikipedia:\nhttp://en.wikipedia.org/wiki/Magnetic_flux\n\nHope this helps!
519039
It really depends.  if you are trying to pass current through the magnet, hooking up the N pole to the + side of the battery, and the S pole to the - side of the battery, then nothing much, other than the magnet may heat up a bit.\n\nIf you are wrapping a copper coil around the magnet and then passing current through the coil, then depending on which way the current is flowing, and how strong a current you are using, you'll either make the magnet stronger, or make the magnet weaker.
131722
OK, so it's a little confusing to me, but apparently the magnetic pole close to the north pole is actually a south magnetic pole.  So for some strange reason, the north pole of a magnet bar will be attracted to the south magnetic pole which is located near the north pole.\n\nNorth poles on a magnet are very easily found.  When you bring a magnet up to a coil, and move the north pole back and forth, you will get a current flow in a particular direction (counter clockwise).  \n\nIf you wish you can create your own magnet.  This way you can decide which end is north, and see which end points north.  You need to pass current in a counter clockwise motion.  Use your right hand and make a thumbs up sign.  Your fingers are pointing in the direction of the current, and your thumb is pointed in the direction of the north field.\n\nBest way is to take a wire and wrap it around a bolt at least 10 times.  Current leaves a battery on the positive terminal and enters the battery on the negative terminal.  Make sure you keep track of the direction of current flow.  Then use the right hand rule I indicated above.  The thumb shows the direction of the north magnetic pole.  I wish I could draw you a diagram.
1182896
Voltage applied to the primary coil of a transfer causes an electrical current to begin to flow, and that causes a magnetic field to form.  As the voltage drops back to zero and reverses, the field collapses and then forms in the opposite direction.  This changing magnetic field induces a voltage in the secondary coil.  If that coil is connected to some load, the voltage causes current to flow.\n\nIf the ferromagnetic core which concentrates and contains the magnetic field is laminated, and there is some room for these laminations to move, they move in response to the changing magnetic field.  If there is no movable magnetic material in the field, you hear nothing.\n\nIt need not be harmonic.  It depends only on how the magnetic material is affected by the force applied to it by the magnetic field, and that field depends on the variation of the applied voltage with time.  It need not be the sinusoidal pattern at 50/60 Hz of commercial power mains.  In a switching power supply, it's a square wave.
775698
An electron, with its negative charge, is surrounded by an electromagnetic field. Normally, in most materials, this field is canceled out by the random positioning of all of the other electrons in the material. \n\nIf these electrons are aligned, the material will become a magnet with the magnetic fields aligned toward one end of the material.\n\nIf the electrons are traveling through the material (current or electrical flow) the magnetic field will be moving with the electrons and will surround the wire (refer to "right hand rule") \nIf the wire is coiled around a piece of iron, for instance, this magnetic field will become very strong and align the electrons in the iron - thus magnetizing the iron.
103677
the phenomenon is called electgromagnetic induction. The incoming signal induces electric current of variying strength in the antenna which is used by the receiving device.
621661
When a charge is moving (current), around its path, there is always eclectic and magnetic field. Energy is stored in these fields.\n\nWhen there is uniform current (no change of current) there is no change in the magnetic field.\n\nBut if the current changes, the energy stored in the magnetic field is spent to oppose the change of current.  That is, the magnetic field varies; eclectic field is induced.\n\nWhen there is a variable current or when a charge is pulsating, there is continuous exchange of energy between the electric and magnetic fields.\n\nAs at every instant there is a change   in these fields we don’t distinguish them as electric or magnetic; but we say that it is electro- magnetic energy. The changes in these fields are transmitted in space. \n\nIn a given volume of space there is full of electro-magnetic field and as the source (pulsating charge or oscillating current) continuously working, energy enters and leaves the volume of space under consideration.\n\nHence there is always electro magnetic energy in a given volume of space and at the same time energy is flowing in and out of the space under consideration.\n\nThis we say radiation of electro magnetic radiation.
612178
When I think of "polarized", I interpret that to mean a system with a fixed, unchanging electric moment.  Electric  containment with static fields is generally not possible within any hollow space.  That's because those particular static fields can always be written as the gradient of a scalar field, the voltage field.  If the space is hollow, with no internal contributing sources, then the forces have zero divergence.  The Laplacian of the scalar field is zero.\n\nA fundamental result of the calculus of multiple variables is that if you have a volume completely enclosed by a surface, and the Laplacian of a scalar field is zero everywhere inside the volume, then the field takes its minimum and maximum values on the surface.\n\nThe energy state of a charged particle in such a field is the produce of the charge and the field value, which we've said is at its minimum and maximum on the surface.  So, either the field is constant everywhere within the container, in which case the container has no influence at all, so there is no containment, or the field is non-constant, and the minimum energy state is obtained when the particle collides with the containment somewhere.\n\nOK, so unchanging electric fields are not going to constrain a charged particle in a hollow space.  How about magnetic fields?  Well, apply a large magnetic field through the space, and inject charged particles into it such that they have no velocity in the direction parallel to the magnetic field, and those particles will orbit in the magnetic field.  If the radius of the orbit is smaller than the distance to the side walls, we can say that the particles have partial containment in the system.  A uniform magnetic field can hold moving charged particles in two dimensions, but provides no containment in the direction parallel to the magnetic field.\n\nIf we start modifying the electric and magnetic fields in more detailed ways, it becomes possible to contain a plasma.  That is, after all, what happens in a Tokamak.