Doubt regarding Force exerted by a magnetic field on a moving charge

In summary, a charged particle moving at velocity V in a region with magnetic field B will experience a force F given by F = q(VxB). When the velocity is 0, the force is also 0. The velocity is relative to the magnetic field and the direction of travel affects the amount of force experienced. If the equation is written in scalar form, the force is equal to the product of the charge, velocity, and magnetic field, multiplied by the sine of the angle between the velocity and magnetic flux density vectors. In cases of relativistic velocities or moving fields, there are electromagnetic transformations that will produce additional components of the electric or magnetic field. These transformations can be found on the LBL Particle Data Group website.
  • #1
ApuroopS
6
0
a charged particle ( say 'q' ) moving with velocity 'V' in a region containing a magnetic field 'B' experiences a force 'F' given by:

F = q(VxB)

when
V = 0,
then force = 0

my doubt is,
is this velocity relative to the magnetic field ?
( i.e. when the velocity relative to the magnetic field becomes = 0, then force due to the magnetic field on the particle = 0 )


i know this question seems nonsensical...but please answer..thanks
 
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  • #2
In a sense, yes it is relative to the B field, but this is hidden in the cross product. The magnitude of the velocity affects the amount of force experienced in the B field but the direction of travel with respect to the polarization of the magnetic flux density also matters. If the charge is moving with the magnetic flux's field lines, then there is no force while the force is maximized if the charge moves normal to the field lines. If you want to have the equation in strictly scalar form then,

[tex] \left| \mathbf{F} \right| = q \left| \mathbf{v} \right| \left| \mathbf{B} \right| \sin \theta [/tex]

Where [tex] \theta [/tex] is the angle between the velocity and magnetic flux density vectors.
 
  • #3
If the observer were moving at a relativistic velocity with respect to a constant E or B field, or a constant E or B field were moving with respect to the observer, then there is an electromagnetic transformation of the longitudinal component that will produce a B or E component. To see the transformations, visit the LBL Particle Data Group website at

http://pdg.lbl.gov/2008/reviews/contents_sports.html

then click on the constants, units, etc. category, then click on the electromagnetic relations section, then look at the last four lines of the table.
 

FAQ: Doubt regarding Force exerted by a magnetic field on a moving charge

How does a magnetic field exert force on a moving charge?

The force exerted by a magnetic field on a moving charge is due to the interaction between the magnetic field and the magnetic dipole moment of the moving charge. The magnetic field exerts a force on the charge perpendicular to both the direction of the charge's velocity and the direction of the magnetic field.

How is the force exerted by a magnetic field calculated?

The force exerted by a magnetic field on a moving charge is calculated using the equation F = qvBsinθ, where F is the force, q is the charge, v is the velocity, B is the magnetic field strength, and θ is the angle between the velocity and the magnetic field.

Can a magnetic field change the direction of a moving charge?

Yes, a magnetic field can change the direction of a moving charge by exerting a force on it. This force is always perpendicular to the velocity of the charge and results in a change in the charge's direction, but not its speed.

Does the strength of the magnetic field affect the force on a moving charge?

Yes, the strength of the magnetic field affects the force exerted on a moving charge. The stronger the magnetic field, the greater the force exerted on the charge. This is because the force is directly proportional to the magnetic field strength.

How does the direction of the magnetic field affect the force on a moving charge?

The direction of the magnetic field affects the force on a moving charge in that the force is always perpendicular to both the velocity of the charge and the direction of the magnetic field. This means that the direction of the magnetic field can influence the direction of the force, but not its magnitude.

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