The presence of a magnetic field is a good indication that:
A)the Earth's interior is similar to Mercury's, as both have fields.
B)a huge iron meteorite lies somewhere high up in the mantle, not in the core.
C)we have a liquid metal outer core, spinning rapidly as we rotate.
D)the Earth's interior must be completely molten to the center.
E)the Earth's interior has had time to solidify, with a rigid bar magnet created.

Question

Quizplus · Accepted Answer

A magnetic field is generated by the motion of electrical charges, and the most likely source of a strong magnetic field such as that of the Earth is a rapidly rotating, electrically conducting fluid in the outer core. This fluid is believed to be molten iron and nickel, and its motion generates the magnetic field that we observe. Choice C accurately describes this scenario. A magnetic field is generated by the movement of a conducting fluid. In the case of the Earth, the most likely source of the magnetic field is the liquid iron outer core, which is spinning rapidly due to the rotation of the planet. This suggests that the Earth has a liquid metal outer core. Choices A, B, and D are not supported by evidence and are unlikely scenarios. Choice E is not supported by the fact that the Earth's magnetic field is not a simple bar magnet but has a more complex structure.

The Presence of a Magnetic Field Is a Good Indication