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General discussionPhysic topic: The Lorentz force(21 posts)solved(21 posts)solved
(21 posts)solved
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This is my favourite topic
Posted February 13, 2015
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jdsgn: The deepest you can go into the 'whys' is starting off with gauge symmetries. I guess that doesn't really help.
The best reason I can intuitively give for the direction of the force a charged particle moving through a magnetic field experiences is accepting that a magnetic field cannot alter the kinetic energy of an electrically charged particle - thus acceleration must not have a component parallel or anti-parallel to the direction of movement. To change the kinetic energy, an object has to have a magnetic moment via which it couples to the field.
I almost understand this and I have a feeling I just need to work at it to get it. This post just became a candidate to be marked as solution.
Posted February 13, 2015
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jdsgn: The deepest you can go into the 'whys' is starting off with gauge symmetries. I guess that doesn't really help.
The best reason I can intuitively give for the direction of the force a charged particle moving through a magnetic field experiences is accepting that a magnetic field cannot alter the kinetic energy of an electrically charged particle - thus acceleration must not have a component parallel or anti-parallel to the direction of movement. To change the kinetic energy, an object has to have a magnetic moment via which it couples to the field.
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justanoldgamer: I almost understand this and I have a feeling I just need to work at it to get it. This post just became a candidate to be marked as solution.
After rereading your original post and doing some research on Faraday's motor, I guess I know what your problem is. If I'm wrong here, please supply some more information on the exact implementation of your motor.
You have a permanent magnet and a current carrying wire, both of which revolve with respect to each other.
In this case, the magnetic field caused by the electric current can be neglected. So, you have electric current from the wire and you have a permanent magnet with its own permanent magnetic field.
Now the wire is placed in such a way that it cuts the magnetic field lines in a right angle. Now charge traveling through the wire experiences a Lorentz force.
Posted February 13, 2015
avatar
justanoldgamer: I almost understand this and I have a feeling I just need to work at it to get it. This post just became a candidate to be marked as solution.
avatar
jdsgn: After rereading your original post and doing some research on Faraday's motor, I guess I know what your problem is. If I'm wrong here, please supply some more information on the exact implementation of your motor.
You have a permanent magnet and a current carrying wire, both of which revolve with respect to each other.
In this case, the magnetic field caused by the electric current can be neglected. So, you have electric current from the wire and you have a permanent magnet with its own permanent magnetic field.
Now the wire is placed in such a way that it cuts the magnetic field lines in a right angle. Now charge traveling through the wire experiences a Lorentz force.
It's like this.

It makes a little more sense now that I know that it's not 2 constant magnetic field interacting that somehow cause the rotation. That's why it does not work with magnets only.

I'm very glad that I decided to restart my electronic hobby with the basics and not accept everything at face value. It does looks like I'll have to review mathematics concept I haven't used in a long time like vectors and calculus.
Posted February 13, 2015
avatar
jdsgn: After rereading your original post and doing some research on Faraday's motor, I guess I know what your problem is. If I'm wrong here, please supply some more information on the exact implementation of your motor.
You have a permanent magnet and a current carrying wire, both of which revolve with respect to each other.
In this case, the magnetic field caused by the electric current can be neglected. So, you have electric current from the wire and you have a permanent magnet with its own permanent magnetic field.
Now the wire is placed in such a way that it cuts the magnetic field lines in a right angle. Now charge traveling through the wire experiences a Lorentz force.
avatar
justanoldgamer: It's like this.

It makes a little more sense now that I know that it's not 2 constant magnetic field interacting that somehow cause the rotation. That's why it does not work with magnets only.

I'm very glad that I decided to restart my electronic hobby with the basics and not accept everything at face value. It does looks like I'll have to review mathematics concept I haven't used in a long time like vectors and calculus.
Remember that the vector product produces a vector that is perpendicular to the two vectors? This is a representation of the fact that the Lorentz force is perpendicular to both the direction of particle movement and the magnetic field lines.
Posted February 15, 2015
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justanoldgamer: It's like this.

It makes a little more sense now that I know that it's not 2 constant magnetic field interacting that somehow cause the rotation. That's why it does not work with magnets only.

I'm very glad that I decided to restart my electronic hobby with the basics and not accept everything at face value. It does looks like I'll have to review mathematics concept I haven't used in a long time like vectors and calculus.
avatar
jdsgn: Remember that the vector product produces a vector that is perpendicular to the two vectors? This is a representation of the fact that the Lorentz force is perpendicular to both the direction of particle movement and the magnetic field lines.
I learned to add and subtract vectors in 2 dimensions and that's about it, I also only learned the basics of calculus. But I have lots of free time, some books, and the internet so I should be able re-learn the basics and then go further than I did in school.
Posted February 15, 2015
avatar
jdsgn: Remember that the vector product produces a vector that is perpendicular to the two vectors? This is a representation of the fact that the Lorentz force is perpendicular to both the direction of particle movement and the magnetic field lines.
avatar
justanoldgamer: I learned to add and subtract vectors in 2 dimensions and that's about it, I also only learned the basics of calculus. But I have lots of free time, some books, and the internet so I should be able re-learn the basics and then go further than I did in school.
Vector calculus up to 3 dimensions is feasible. Some things might seem strange at first, but there is almost always an understandable representation of calculations.
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General discussionPhysic topic: The Lorentz force(21 posts)solved(21 posts)solved
(21 posts)solved