Which function is performed by Earth’s magnetic field?

• A. It is responsible for the majority of Earth’s heat flow from the interior to the surface.
• B. It deflects and traps charged particles from the solar wind, reducing harmful radiation at Earth’s surface.
• C. It produces most of Earth’s gravitational attraction on objects near the surface.
• D. It directly causes the daily cycle of ocean tides by exerting a strong magnetic pull on seawater.

Answer: (B)

Verified step by step guidance

1. Understand the role of Earth's magnetic field: It is generated by the motion of molten iron in Earth's outer core, creating a magnetic shield around the planet.
2. Recognize that Earth's magnetic field interacts with charged particles from the solar wind, which are streams of charged particles emitted by the Sun.
3. Know that the magnetic field deflects and traps many of these charged particles, preventing them from directly hitting Earth's surface and thus reducing harmful radiation exposure.
4. Distinguish this function from other Earth processes: Earth's heat flow is mainly due to geothermal energy, gravitational attraction is due to Earth's mass, and ocean tides are primarily caused by the gravitational pull of the Moon and the Sun, not magnetic forces.
5. Conclude that the primary function of Earth's magnetic field is to protect the planet by deflecting and trapping charged solar particles, thereby reducing harmful radiation at the surface.