Which statement about lines of force and poles is correct?

Which statement about lines of force and poles is correct?

• A. Lines of force emerge from the North pole and terminate at the South pole.
• B. Lines of force emerge from the South pole and terminate at the North pole.
• C. Lines of force do not interact with poles.
• D. Lines of force require current to exist.

Answer: (A)

Magnetic field lines show the direction of the magnetic field and how it threads through space. For a bar magnet they are drawn as leaving the North pole, traveling through the surrounding space, and entering the South pole. Inside the magnet, the path continues from South back to North, so the lines form a continuous loop. This convention makes the external field point away from the North and toward the South, which is why the statement that lines emerge from the North pole and terminate at the South pole is the accurate description. Lines do interact with poles by beginning and ending at them, and they can exist without any current—permanent magnets produce a field on their own, while current in a wire is another way to generate magnetic fields. The other options either flip the direction, deny interaction with poles, or claim current is required, which aren’t correct in this context.

Magnetic field lines show the direction of the magnetic field and how it threads through space. For a bar magnet they are drawn as leaving the North pole, traveling through the surrounding space, and entering the South pole. Inside the magnet, the path continues from South back to North, so the lines form a continuous loop. This convention makes the external field point away from the North and toward the South, which is why the statement that lines emerge from the North pole and terminate at the South pole is the accurate description.

Lines do interact with poles by beginning and ending at them, and they can exist without any current—permanent magnets produce a field on their own, while current in a wire is another way to generate magnetic fields. The other options either flip the direction, deny interaction with poles, or claim current is required, which aren’t correct in this context.