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Name: Chris
Status: student
Age: 12
Location: N/A
Country: N/A
Date: 2/26/2003

Why is it that magnetic field lines do not cross each other?

Magnetic field lines indicate the direction of the magnetic field, which is always tangent to a field line. If the lines crossed, the magnetic field would be pointing in two directions at the point of crossing. Apart from being logically unpleasant, it would mean that the magnetic force on a charged particle passing through that point, which must be perpendicular to the magnetic field, would be in two different directions at the same time.

The same arguments work for electric field lines. It's easier to see there, since the electric force on a charged particle is in the direction of the electric field.

Best, Dick Plano, Professor of Physics emeritus, Rutgers University


A magnetic field can only point in one direction at a time. The direction of the field line at a location is also the direction of the magnetic field at that same place. If the field lines crossed at one location, the magnetic field would have two different directions at one location. It would point two different ways at once.

Dr. Ken Mellendorf
Physics Instructor
Illinois Central College

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