Magnetic fields and charged particles

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A charged particle experiences a force in a magnetic field described by F = qV x B, indicating no force when the particle's velocity is zero. If the magnetic field is moving or changing, the particle's kinetic energy can be affected, as described by Maxwell-Faraday's law, which states that a time-varying magnetic field generates an electric field. In this scenario, the particle's frame of reference can lead to different calculations, necessitating the use of induction laws instead of the basic force equation. The discussion highlights that while the standard equation is simpler, understanding the implications of changing magnetic fields is crucial. Overall, the relationship between magnetic fields and charged particles is complex and tied to fundamental electromagnetic principles.
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It has been stated that a charged particle in the vicinity of a magnetic field experiences a force given by F = qV x B, which states that there is no force when its velocity is zero. It also shows that only the particles direction can be changed, not its kinetic energy.

My question is this: what if you take the frame of reference that the particle has zero velocity and the magnetic field is moving (or changing)? Or simply, you have a stationary charge and pass a magnetic field by it?

In this context, is the kinetic energy of the particle then changed?

If so, is this at all related to, or the base idea of induction?
 
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When you use F=qv×B this equation, v must be in reference to a non-changing B. If you want to use the reference frame in which the particle is the center of coordinates (ie. v=0), then you must use the induction laws, specifically:

E.dl = -(d/dt)∫∫B.dS, and F=qE

PS. It's so much easier to just use F=qv×B.
 
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Thread 'Correct statement about size of wire to produce larger extension'
The answer is (B) but I don't really understand why. Based on formula of Young Modulus: $$x=\frac{FL}{AE}$$ The second wire made of the same material so it means they have same Young Modulus. Larger extension means larger value of ##x## so to get larger value of ##x## we can increase ##F## and ##L## and decrease ##A## I am not sure whether there is change in ##F## for first and second wire so I will just assume ##F## does not change. It leaves (B) and (C) as possible options so why is (C)...

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