Magnetic field lines around a current-carrying conductor form closed loops around the conductor.

Magnetic field lines around a current-carrying conductor form closed loops around the conductor.

• A. False
• B. Sometimes
• C. Never
• D. True

Answer: (D)

Magnetic field lines are continuous, with no ends. Around a current-carrying conductor, the field wraps around the wire in circular loops, so every line forms a closed path encircling the conductor. This circular structure comes from the fact there are no magnetic monopoles, so the magnetic field has divergence zero and lines cannot start or finish in space. The direction around the wire is given by the right-hand rule, reinforcing that the lines are closed circles around the current. So the statement is true because the magnetic field around a straight current is circumferential, producing closed loops. The alternatives don’t fit: depending on the phrasing, lines never start or end, and thus cannot be open-ended or intermittent around a conductor.

Magnetic field lines are continuous, with no ends. Around a current-carrying conductor, the field wraps around the wire in circular loops, so every line forms a closed path encircling the conductor. This circular structure comes from the fact there are no magnetic monopoles, so the magnetic field has divergence zero and lines cannot start or finish in space. The direction around the wire is given by the right-hand rule, reinforcing that the lines are closed circles around the current.

So the statement is true because the magnetic field around a straight current is circumferential, producing closed loops. The alternatives don’t fit: depending on the phrasing, lines never start or end, and thus cannot be open-ended or intermittent around a conductor.