When you drop a strong magnet through the center of a copper pipe, the magnet
A) descends slowly because it is attracted to the magnetic copper metal.
B) descends rapidly because its motion causes currents to flow in the pipe and those currents attract the magnet.
C) falls at the usual rate because copper metal is nonmagnetic.
D) descends slowly because its motion causes currents to flow in the pipe and those currents repel the magnet.

Question

Quizplus · Accepted Answer

The magnet descends slowly through the copper pipe due to Lenz's Law, which states that the induced currents (eddy currents) in the copper pipe will create magnetic fields that oppose the magnet's motion, effectively slowing its descent. Copper is not magnetic, but it is a good conductor, so the magnet's motion induces these currents.

When You Drop a Strong Magnet Through the Center of a Copper