In my high school days we were drawing Magnetic lines of force over a magnet,which was what i found weird. as far as i know magnetic lines of force are nothing but imaginary motion of attraction of oposite poles,in such a way that if monopoles ever existed,(HYPOTHETICALLY)then this is how they"ll possibly move.the attraction is there,the field around a magnet is in the same way as the lines of force are drawn and even the flux around a place near to magnet is found to be the same. Ny question is,if this is hypothetical motion of poles(Mono Poles to be specific)then what exactly are Magnetic lines of force? curious... bye!
Ny question is,if this is hypothetical motion of poles(Mono Poles to be specific)then what exactly are Magnetic lines of force? Magnetic "lines of force" is a term coined by Faraday. They are actually magnetic 'field lines' which are basically the structure of magnetic fields in three dimensions. For example, with a bar magnet (dipole), the field lines converge where the force is strongest (near the poles) and spreads out where the force is weakest. If you place an ideal compass needle (free moving) anywhere in the magnetic field, the needle will always point along the direction of the field line. The Earth's magnetic field is very similar. Plasma in space (ion/electron gas) flows freely and easily along these field lines, hence it's structure is dictated by the Earths magnetic lines of force.
What Q said, only, bear in mind that These feild lines do not 'actually exist'. They are a construct to help people visualize the field. You see, Faraday's math was atrocious, and he tried to do as best he could without. So he was forced to think about these things visually, and feild lines are the result. Well to hell with 'actually exists', we're theoretical physicists!
It's a line of equal potential energy. The actual physical components run perpendicular to the field lines.
It's a graphic representation of an invisible force that's useful to visualize it's location and relative strength.
Try picking up some iron filings with a bar magnet, or better, see what happens when you put some filings in a glass jar, and use a nice strong magnet (on the outside of the jar), like out of an old electric motor.
Would it be accurate to define a magnetic field line as a continuous curve such that the tangent to the line at any point is parallel to the magnetic field vector at that point? I am trying to decide in my own mind if that is a necessary and sufficient condition.
Say there are two points on a 2 dimensional surface that are along the same field line. Pick two points that are almost infinitely close together. Take the perpendicular of that line, and that's the direction of the actual field (usually emanating away from the source). The lines represent the locations where X-Voltage occurs around the 3 dimensional object. That voltage will occur around the object at every point in space, the distance from the object might be variable. Thus the field lines are the lines that are of equal-potential. Moving to a field line of equal potential out further will lead to a voltage of equal potential LESS than X.
Not sure what you mean by "actual physical components"? Of what? Yes. That's exactly what a field line is. The magnetic force on a charged particle in the field is a different matter (and perhaps this is what CheskiChips meant). The magnetic force on a moving charged particle is perpendicular to both the velocity of the particle and to the magnetic field direction.
This is not how field lines are defined. The direction of the field vector at any point is tangent to the field lines, not perpendicular to them. A few points here: 1. Potential (voltage) relates to electric fields, not magnetic fields. 2. Equipotential lines (lines connecting equal "voltages") are not the same thing as field lines. In fact, equipotential lines are perpendicular to field lines everywhere. In other words lines of equal electrical potential are perpendicular to electric field lines. 3. It is possible to define a kind of "magnetic potential" in certain circumstances, but magnetic potentials are not voltages. In fact, the most logical definition of magnetic potential is the magnetic vector potential, which is something of a complicated beast.
Yeah you're right; I've never applied ol' University Physics II since I took it. Thanks for the refresher.
Physical manifestation of lines of force Try getting some ferrofluid and look at the 3-D manifestation of lines of force. They are similar to electromagnetic lines of force. Maxwell described lines of force...but could there be a spectrum - a frequency - when someone asks what they are - the explanations so far are unsatisfactory. When you look at sound waves represented by salt on a surface that is vibrating they represent nodes. Do magnetic lines of force represent nodes of .....?
In this entire discussion no one has used the term straight line which is so descriptive of all emanations here in the physical world.
