Final answer:
The difference between a uniform and non-uniform magnetic field is based on the consistency of field strength and direction; uniform fields are consistent throughout, while non-uniform fields vary. To discern between a uniform electric or magnetic field in a region, one can observe the motion of a charged particle introduced to that region.
Step-by-step explanation:
The difference between a uniform magnetic field and a non-uniform magnetic field lies in the consistency of the field's strength and direction across a given area. In a uniform magnetic field, the strength and direction of the field lines are consistent at every point within the field. This can be visualized with equally spaced, parallel field lines. Conversely, in a non-uniform magnetic field, the strength and/or direction of the field varies from one point to another, resulting in field lines that may converge, diverge, or have varying densities.
To distinguish whether a certain region has a uniform electric or magnetic field, one may perform specific measurements or observations. For instance, if a charged particle is introduced to the region and moves with a constant velocity without being deflected, this would indicate a uniform electric field, assuming the charges are at equilibrium. On the other hand, a charged particle moving in a circular or helical path suggests the presence of a magnetic field due to the Lorentz force acting perpendicular to the particle's velocity.