- #1
Andrew Bernard
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I'm having some confusion about the creation of magnetic field lines. How I understand it so far, is that a magnetic field is basically an electric field viewed from a relative point. I don't have a great understanding so far, as I just started to learn about it, but I've learned that objects traveling fast condense together (something due to special relativity) relative to non-moving objects, so there would be a higher charge density on the moving object.
Starting at 1:10 in this video, he explains why the magnetic field exists.
He goes on to show that the magnetic field will exist and exert a force on the proton when the proton is moving. BUT what I don't understand is when the proton is stationary in that video, and the electrons are flowing, why don't the electrons condense and exert an attractive force on the proton?
This kind of goes along with my first question. I've also watched a couple other videos explaining that when an object is not moving, no magnetic force is acted upon it (I'm hoping that's true, and I that my first question covers this). So when a wire with a current flowing through it is placed over a compass, why does the compass needle move? It moved, so that should mean that there was a force applied to it. But the compass needle wasn't moving, so what force caused it to move? I thought that there should be no magnetic force acting on a stationary object? So if the compass needle was stationary, how did a magnetic force act on it.
So I guess my fundamental question is this: If you create a magnetic field along a wire, by inducing a current along a straight wire, will a positively charged object experience a magnetic force? Why or why not? If it does, will it be attracted or repelled? If it doesn't experience a force, then how and why does a compass needle move when it is near a wire that has current flowing through it?
When I say that a stationary object should experience no magnetic force I'm referring to this video at 1:20:
Hopefully my questions weren't too confusing, and thanks in advance for any help!
Starting at 1:10 in this video, he explains why the magnetic field exists.
He goes on to show that the magnetic field will exist and exert a force on the proton when the proton is moving. BUT what I don't understand is when the proton is stationary in that video, and the electrons are flowing, why don't the electrons condense and exert an attractive force on the proton?
This kind of goes along with my first question. I've also watched a couple other videos explaining that when an object is not moving, no magnetic force is acted upon it (I'm hoping that's true, and I that my first question covers this). So when a wire with a current flowing through it is placed over a compass, why does the compass needle move? It moved, so that should mean that there was a force applied to it. But the compass needle wasn't moving, so what force caused it to move? I thought that there should be no magnetic force acting on a stationary object? So if the compass needle was stationary, how did a magnetic force act on it.
So I guess my fundamental question is this: If you create a magnetic field along a wire, by inducing a current along a straight wire, will a positively charged object experience a magnetic force? Why or why not? If it does, will it be attracted or repelled? If it doesn't experience a force, then how and why does a compass needle move when it is near a wire that has current flowing through it?
When I say that a stationary object should experience no magnetic force I'm referring to this video at 1:20:
Hopefully my questions weren't too confusing, and thanks in advance for any help!
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