A sphere carries negative charge. Which way do its electric field lines point?
So far you have read field diagrams other people drew. In this lesson, you build one. The target is the field around a lone positive charge.
A correct radial sketch comes from three decisions, made in order.
Decision 1 is direction: which way do the arrows point? Electric field lines point away from positive charge, so every arrow points out from this source. Toward a negative charge, the arrows would point in. Toward a mass, the arrows would also point in.
Vera sketches the field around a lone negatively charged sphere. Which way do her field lines point?
Decision 2 is the lines themselves: straight lines along radii, spread evenly around the source, each line carrying an arrowhead.
Decision 3 is spacing: a radial field weakens with distance, so the gaps between lines widen farther from the source.
Moving farther from a lone charged sphere, what happens to the gaps between its field lines?
Build the sketch of the field around a lone asteroid, decision by decision.
Decision 1, direction: field lines point toward a mass, so every arrow points in toward the asteroid.
Decision 2, lines: straight lines along radii, spread evenly around the asteroid, each with an arrowhead.
Decision 3, spacing: the field weakens with distance, so the gaps widen farther from the asteroid.
The sketch shows straight lines along radii, arrows in toward the asteroid, gaps widening with distance.
Check any sketch against the three decisions, and the sketch is done.
A correct field sketch around a lone positively charged marble has which set of features?
Vera and Idris each sketch the field around a positively charged door knob. Vera's arrows point out from the knob; Idris's arrows point in toward it. Whose direction is correct?
The table lists the features of Casper's sketch of the field around Mars. Which change makes the sketch correct?
Polly sketches two fields: one around a positively charged pin, one around a lone boulder drifting in space. In which sketch do the arrows point out away from the source?