Magnet vs CRT TV a.k.a question about magnetic poles of electrons

In summary, when watching some videos about neodymium magnets, the maker put a large magnet near an old CRT TV. This caused electrons to be repelled from the magnet and not hit the screen. After he turned the magnet around, the electrons rushed to the magnet and created one illuminated spot, leaving the other parts of the screen dark. My question is, why are the magnetic poles of the electrons emerging from the cathode all lined up in the same direction and why don't they 'turn around'?
  • #1
Dummienoob
9
0
When watching some videos about neodymium magnets, I came upon a very interesting phenomenon. Namely, the maker of the video put a large magnet near an old CRT TV.

At first, a big black spot appeared on the screen. This means that the electrons were repelled from from the magnet and didn't hit the screen. After that, he turned the magnet around and approached the screen again. This time, the electrons rushed to the magnet and created one illuminated spot, leaving the other parts of the screen dark.

My question is, why are the magnetic poles of the electrons emerging from the cathode all lined up in the same direction and why don't they 'turn around'? When I approach 1 big magnet's south pole with some small magnets' south pole, the small magnets always turn around, exposing their north pole and are attracted to the big one instead of reataining the same position and being repelled.
 
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  • #3
Yes, I know that moving charged particles are affected by magnetic fields. But that means that 1 pole of the magnet attracts negative charge and the other one repels it. From that can we derive that one pole of the magnet has + charge and the other one has - charge or not?
 
  • #4
Dummienoob said:
Yes, I know that moving charged particles are affected by magnetic fields. But that means that 1 pole of the magnet attracts negative charge and the other one repels it. From that can we derive that one pole of the magnet has + charge and the other one has - charge or not?

Charged particles are affected by magnetic fields, but not the way that you're thinking. The magnetic force a charged particle experiences depends on the particle's speed and direction. There is no force at all if the particle is not moving; if it is moving the force is at right angles to the direction of movement. There's no arrangement of electrical charges that will produce these effects, so it doesn't work to think about the poles of a magnet as if they're charged.

The force on a particle with charge ##q## moving with velocity ##\vec{v}## in a magnetic field ##\vec{B}## is ##\vec{F}=q\vec{v}\times\vec{B}## where the ##\times## operation is the vector cross-product.

Google for "Lorentz force" for more information.
 
  • #5
Heads up: Don't try this with a TV unless you want to ruin it.
 
  • #6
The magnet is likely interfering with the internal workings of the TV... But, without the reference, it is not possible to be sure.
It is unlikely that the offered explanation re post no 1 is correct.
Please provide a link or a reference to the video.
 

1. What is the difference between a magnet and a CRT TV?

A magnet is a material that produces a magnetic field and attracts certain metals, while a CRT TV (cathode ray tube TV) is a type of television that uses a vacuum tube to display images. The magnet in a CRT TV is used to guide the electron beams onto the screen.

2. How do magnets and CRT TVs work?

Magnets work by having north and south poles that attract or repel each other. In a CRT TV, the magnet is used to control the direction of the electron beams, which then hit the screen to create an image.

3. Can magnets affect the functioning of a CRT TV?

Yes, magnets can affect the functioning of a CRT TV because they can interfere with the electron beams and distort the image on the screen. It is important to keep magnets away from CRT TVs to avoid any interference.

4. What are the magnetic poles of electrons?

Electrons themselves do not have magnetic poles. However, when electrons are in motion, they create a magnetic field and can be influenced by external magnetic fields. This is how magnets and CRT TVs work together.

5. Are there any risks associated with magnets and CRT TVs?

There may be some risks associated with strong magnets and CRT TVs, as the magnets can cause interference and distort the images on the screen. Additionally, strong magnetic fields can also potentially damage the vacuum tube inside the TV. It is important to handle magnets and CRT TVs with caution to avoid any hazards.

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