Answer: declination.
- A declination
- B the dip angle
- C the incidence
- D the refraction
Correct answer: A. declination
Explanation: Declination is the horizontal angle between true (geographic) north and magnetic north.
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.