Stationary point charge in increasing magnetic field

[jimmyjets]

hi everyone, if a stationary point charge is placed in an increasing magnetic field, is the force on the charge due to the magnetic field = 0?
because Fb = qv*B and v=0

then how would I derive the magnitude of the force on the charge due to the magnetic field with the magnetic field increasing at dB/dt?
thanks

 

[Mindscrape]

The Lorrentz force law is actually

[tex]F = q \mathbf{v} \times \mathbf{B}[/tex]

It doesn't matter how your magnetic field is changing, if you have no velocity then you will not have any magnetic force acting on the object. Magnetism, from a relative standpoint, is the study of changing electric fields, which you don't have. It is the study of moving charges. If you don't have any current running through a wire, does it have a magnetic field? No, the charges aren't moving. The same thing applies here, your charge isn't moving so there isn't a field to interact with.

The same is true if the velocity and magnetic fields are parallel, no matter how fast the particle accelerates or how much the magnetic field changes the force will be zero.

 

[m2003]

I would like to clarify that the equation Fb = qv*B represents the force on a moving charge in a magnetic field, where v is the velocity of the charge and B is the magnetic field. For a stationary point charge, the force due to the magnetic field would be zero since v=0, as you correctly stated.

However, if the magnetic field is increasing at a rate of dB/dt, there will be a changing magnetic flux passing through the stationary charge. This changing magnetic flux will induce an electric field, which will result in a force on the charge. This phenomenon is known as electromagnetic induction.

To calculate the magnitude of this force, you can use the equation F = qv*B*dB/dt, where q is the charge of the particle, v is its velocity, B is the magnetic field, and dB/dt is the rate of change of the magnetic field. This equation is derived from Faraday's law of electromagnetic induction.

In summary, the force on a stationary point charge in an increasing magnetic field is not zero, but rather it is dependent on the rate of change of the magnetic field. I hope this helps clarify your question.