Do Magnetic Dipoles Produce Opposite Field Directions?

AI Thread Summary
Magnetic dipoles produce field lines that indicate the direction of the magnetic field, with the field being defined as a vector quantity. The discussion highlights confusion regarding the interpretation of magnetic field direction, particularly when considering negative values in a coordinate system. It emphasizes that the negativity of a vector field is not inherently defined, as magnetic fields are geometrical objects. The application of Lenz's law in relation to a moving dipole and its effect on a circular wire is also explored. Ultimately, the conversation clarifies that understanding the behavior of magnetic field lines and their interaction with dipoles is crucial for grasping the underlying physics.
Frank Einstein
Messages
166
Reaction score
1
Hello, I have recently been doing homework about magnetic dipoles, and one doubt has come to my mind; Does a dipole pointing in ine direction produces a negative field in the contrary?.
http://en.wikipedia.org/wiki/Dipole#mediaviewer/File:VFPt_dipole_point.svg
That is what this image seems to sugest.
And the equation http://data:image/jpeg;base64,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 seems to comfirm it for negative r, but for me this seems a little weird.
Can anyone confirm this?
Since the images don't work, the first one is the standard drawing of the dipole's field and the second is the standar formula for B, the first one which appears on wikipedia
 
Physics news on Phys.org
What do you mean by 'negative'? Magnetic field is usually represented as a 3-D vector field. I don't the negativity of a vector field is actually defined since it is a geometrical object. Perhaps, you mean the components in a specific coordinate system. But then you need to define the coordinate system.

And which bit exactly that you feel weird about?
 
Actually I am trying to apply Lenz's law to a circular wire and a dipole which is moving on the z axis. The wire is on the plane z=0 and the dipole is at z>0 on the centre of the wire, so it is the z coordinate the component the one which is moving.
And what I feel weir about is that I normaly don't extract the geomretrical meaning of a drawing, but I focus on extracting information from the equations I have at hand, so I don't have much experience with this.
 
I think along the central axis, the magnetic flux density is alone the same direction. It is a common feature in sourceless fields to satisfy Gauss Laws, but to satisfy Ampere's law the off-axis z components have to be negative in some regions.

The drawing of magnetic field is representing the direction of flux density, and I think it is very literal. I do not understand where to confuse about
 
Well, I was confused about how the interpretation of the camp lines passing through a region of space and how the movement of the dipole changed them, but I have already understood it. Thanks for your anwser.
 
Thread 'Inducing EMF Through a Coil: Understanding Flux'

Thread 'Inducing EMF Through a Coil: Understanding Flux'

Thank you for reading my post. I can understand why a change in magnetic flux through a conducting surface would induce an emf, but how does this work when inducing an emf through a coil? How does the flux through the empty space between the wires have an effect on the electrons in the wire itself? In the image below is a coil with a magnetic field going through the space between the wires but not necessarily through the wires themselves. Thank you.
View full post »
Thread 'Griffith, Electrodynamics, 4th Edition, Example 4.8. (Second part)'

Thread 'Griffith, Electrodynamics, 4th Edition, Example 4.8. (Second part)'

I am reading the Griffith, Electrodynamics book, 4th edition, Example 4.8. I want to understand some issues more correctly. It's a little bit difficult to understand now. > Example 4.8. Suppose the entire region below the plane ##z=0## in Fig. 4.28 is filled with uniform linear dielectric material of susceptibility ##\chi_e##. Calculate the force on a point charge ##q## situated a distance ##d## above the origin. In the page 196, in the first paragraph, the author argues as follows ...
View full post »

Hot Threads

Recent Insights

Back
Top