To show that the magnetic force changes with increase or decrease in temperature of the magnet.
- A medium sized magnet.
- Gem clips.
- Blow dryer.
- Bring the magnet close to the gem clips. Some of them will be attracted to the magnet. Count the no. of clips that gets attached to the magnet.
- Now keep the magnet in the refrigerator, preferably the freezer section, for about 20 minutes. Now bring the cold magnet close to the gem clips again. Check how many clips are attracted by this cold magnet.
- Use blow dryer to increase the magnet’s temperature by blowing hot air on the magnet for about 10 minutes. Now bring this hot magnet close to the gem clips again. Check how many of clips are attracted.
We see that the unchanged magnet picked up the most no. of clips. On the other hand the frozen and the hot magnet picked up less no. of clips. The frozen and the heated magnet picked up approximately 10% and 20% less no. of clips, respectively. Thus, both heating and freezing the magnet decreased its strength. Heating the magnet decreased the magnet’s strength the most because the hot magnet picked up almost two times less than the frozen magnet.