Answer: bar magnet.
- A bar magnet
- B capacitor
- C resistor
- D battery
Correct answer: A. bar magnet
Explanation: The Earth acts like a huge bar magnet tilted slightly from its rotation axis.
Magnetic field lines form closed loops: outside the bar magnet they run from the N pole to the S pole; inside, they continue from S back to N, so the lines never start or end anywhere.
Concept context
Bar magnets, Earth's magnetism, and how different materials respond to an external magnetic field - diamagnetic, paramagnetic, and ferromagnetic behaviour.