Uniform or radial? Sort a field by its lines

In one field, the force on a given object keeps the same strength and direction at every point. Is the field uniform?

You have the two names: uniform and radial. Many field drawings are one or the other, and one look at the lines tells you which.

The sort runs on one question: what do the lines do?

The rule is the pair you learned: a uniform field's lines are parallel and evenly spaced; a radial field's lines run along radii and spread apart with distance.

This field is uniform, because its lines are parallel and evenly spaced. (The field in a classroom.)

But this field is radial, because its lines run along radii and spread apart. (The field around Jupiter.)

And this field is also radial, because its lines run along radii and spread apart. The arrows point outward this time; the arrow direction does not change the sort. (A positively charged dome.)

But this field is uniform, because its lines are parallel and evenly spaced. (The field in a warehouse.)

One sentence settles every case: lines that stay parallel and evenly spaced show a uniform field; lines that fan out from a center show a radial field.

One more, with no drawing. Around Venus, the field lines point inward along radii, spreading apart with distance. The lines run along radii, so the field is radial.

The diagram shows the field lines above a soccer field. Is the field uniform or radial?

The diagram shows the field lines around the Moon. Is the field uniform or radial?

The diagram shows the field lines around a positively charged sphere. Is the field uniform or radial?

The diagram shows the field lines inside a gym. Is the field uniform or radial?

The diagram shows the field lines above a parking lot. Is the field uniform or radial?

The diagram shows the field lines around a negatively charged ball. Is the field uniform or radial?

Your turn

Which diagram shows a uniform field?

A field is classified as radial. Which feature of its lines decides the classification?

A positively charged dust speck hangs alone at the center of a room. What pattern do the speck's electric field lines form?