Does a hot magnet pick up fewer metal pieces than a cold one? Permanent magnets can lose pulling power as their temperature rises. The change can be dramatic across a wide range.
You test five magnets at temperatures from 0°C to 100°C. At each temperature, you press a magnet into a tray of steel washers and count how many stick. The frozen magnets start near 0°C after a night in the freezer. A hot plate brings them up to higher temperatures.
At 0°C the magnets grab around 30 washers. At 100°C they pick up fewer than 10.
Hypothesis
The hypothesis is that increasing the temperature of a magnet reduces its strength.
The invisible force around a magnet can weaken when the magnet heats up. You test five magnets at temperatures from 0°C to 100°C, pressing each one into a tray of steel washers and counting how many stick. At 0°C the magnets grab around 30 washers. By 100°C they pick up fewer than 10 — a dramatic drop across that range.
The force that makes magnets pull iron objects toward them can weaken with heat. Permanent magnets lose pulling power as their temperature rises. You test five magnets at temperatures from 0°C to 100°C by pressing each one into a tray of steel washers and counting how many stick. At 0°C the magnets grab around 30 washers. At 100°C they pick up fewer than 10.
Heat changes more than just temperature — it can also weaken a magnet's pulling power. You test five magnets at temperatures from 0°C to 100°C. At each temperature you press a magnet into a flat tray of steel washers and count how many stick. At 0°C the magnets grab around 30 washers. At 100°C they pick up fewer than 10. That steep drop shows how dramatically rising temperature reduces magnetic strength.
Method & Materials
You will measure the temperature of the magnets, spread steel washers on a tray, and count the number of washers that stick to the magnet at different temperatures.
You will need 5 magnets, 200 steel washers, a flat tray, a hot plate, an infrared thermometer, a refrigerator, and a pair of gloves.
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The results showed that as the magnet's temperature increased, the number of washers picked up by the magnets decreased. This proves that increasing the temperature of a magnet reduces its strength.
Why do this project?
This science project is interesting because it explores the relationship between temperature and magnetism, which is a phenomenon that is used in many everyday items.
Also Consider
Consider repeating the experiment using an electromagnet, or using magnets made from different materials.
Full project details
Additional information and source material for this project are available below.
