A metal rod is falling toward the surface of the Earth near the equator. As it falls, one end of the rod becomes positively charged due to the motional emf of the rod through the Earth's magnetic field. The rod is oriented so that:

Question

Quizplus · Accepted Answer

As the rod falls through the Earth's magnetic field, the motion of the rod induces an emf due to the Lorentz force. Near the equator, the Earth's magnetic field is approximately horizontal and points from south to north. Using the right-hand rule, with the velocity of the rod downward and the magnetic field pointing north, the induced current will cause the positive charge to accumulate on the east end of the rod.

A Metal Rod Is Falling Toward the Surface of the Earth