Earth's magnetic field
A) is variable, and it has faded to zero and returned to full strength with the polarity reversed.
B) is constant in its intensity.
C) remains a mystery as to its cause.
D) is principally generated in the inner core.

Question

Quizplus · Accepted Answer

Earth's magnetic field is variable and has reversed polarity in the past. It is generated by the motion of molten iron in the outer core, not the inner core.

Earth's Magnetic Field