Magnetism and Moving Charges
Describe the magnetic field produced by moving charged objects.
- A single moving charged object produces a magnetic field.
- The magnetic field at a particular point produced by a moving charged object depends on the object’s velocity and the distance between the point and the object.
- At a point in space, the direction of the magnetic field produced by a moving charged object is perpendicular to both the velocity of the object and the position vector from the object to that point in space and can be determined using the right-hand rule.
- The magnitude of the magnetic field is a maximum when the velocity vector and the position vector from the object to that point in space are perpendicular.
Describe the force exerted on moving charged objects by a magnetic field.
- Magnetic forces describe interactions between moving charged objects.
- A magnetic field may exert a force on a charged object moving in that field.
- The magnitude of the force exerted by a magnetic field on a moving charged object is proportional to the magnitude of the charge, the magnitude of the charged object’s velocity, and the magnitude of the magnetic field and also depends on the angle between the velocity and magnetic field vectors. Relevant equation:
- The direction of the force exerted by a magnetic field on a moving charged object is perpendicular to both the direction of the magnetic field and the velocity of the charge, as defined by the right-hand rule.
- In a region containing both a magnetic field and an electric field, a moving charged object will experience independent forces from each field.
- The Hall effect describes the potential difference created in a conductor by an external magnetic field that has a component perpendicular to the direction of charges moving in the conductor.
Quantitative treatment of the magnitude of the magnetic force exerted by a magnetic field on a moving charge is limited to angles of 0, 90, and 180 degrees between the velocity and the magnetic field. Qualitative analysis of other angles is permitted.