A student sketches several magnetic field lines for a single bar magnet but draws two…
PHYSICS · Single correct · AP · Physics 2: Algebra-based · Magnetism and Electromagnetism · Magnetism and Electromagnetism
Problem
A student sketches several magnetic field lines for a single bar magnet but draws two of the lines crossing each other outside the magnet. Which of the following is the BEST explanation of why the sketch is physically incorrect?
(a) Field lines cannot cross because at any point the magnetic field has a single well-defined direction.
(b) Field lines cannot cross because magnetic monopoles do not exist in nature.
(c) Field lines cannot cross because doing so would violate the rule that magnetic field lines must form closed loops.
(d) Field lines cannot cross because the magnitude of the magnetic field is the same everywhere outside a magnet.