If the magnetic field from a long, straight, current-carrying wire has a magnitude B₀ at a distance d, what is the magnitude of the field at a distance 2d? A) also B₀ B) 0.707 B₀ C) 0.693 B₀ D) B₀/2 E) B₀/4

Question

Quizplus · Accepted Answer

The magnetic field from a long, straight, current-carrying wire decreases with distance as the inverse distance. That is, if the field at a distance d is B₀, then at a distance 2d, the field would be B₀/2. Therefore, the correct answer is D.

If the Magnetic Field from a Long, Straight, Current-Carrying Wire