Evaluate Field Investigations Practice Test

A student uses a compass to investigate a magnetic field and records the direction of the needle at many points around a magnet. The student’s data show that the needle direction changes smoothly from point to point (not randomly).

Why does a smooth, organized pattern make the evidence for a field stronger?

A student investigates an electric field by holding a charged rod near an electroscope at 5, 10, 15, and 20 cm (no contact). The leaves separate at all distances, but the student wants to better show how far the field reaches (its extent).

Which change would best address this goal?