Jill uses a magnet to pick up a nail. Then she touches the nail to a paper clip and picks up the paper clip. What will most likely happen when she pulls the magnet away from the nail?

• A. The paper clip will stay attached to the nail because the nail is now a permanent magnet.
• B. The paper clip will fall off of the nail because the nail was only a temporary magnet.
• C. The paper clip will stay attached to the nail because the paper clip is now a permanent magnet.
• D. The paper clip will fall off of the nail because the nail is now magnetized in the opposite direction.

Answer: (B)

The key idea is that magnetism can be induced temporarily in iron and steel. When a strong magnet is near a nail, the magnetic domains in the nail line up, so the nail itself becomes a temporary magnet. That’s why the magnet can pull the nail up. If the nail then contacts a paper clip, the nail can magnetize the clip as well, so the clip can be picked up too. But this magnetization only lasts while the external magnetic field is present. Once you pull the magnet away, the magnetic alignment falls apart and both the nail and the paper clip lose their magnetization. Without the magnetic force holding them together, the paper clip will fall off.