Magnetic Science Fair Projects, Part 1: How Permanent Magnet Strength Varies with Temperature
Has your kid been brainstorming ideas for their next science fair or school project? If you want to help them get a little more creative than a paper mache volcano (no judgment; we love a good volcano as much as the next person!), then consider suggesting a magnet implementation for the next project.
Not only do magnets make for fun and exciting scientific displays, but they’re also extremely applicable to day-to-day life. It’s a great way for kids to learn and present all the ways that magnets are used in practical and important ways.
This is part one of a three-part series in which we’ll share specific ideas for magnetic science fair projects, including a list of materials and a step-by-step guide.
Remember, always handle magnets with care. Refer to our safety tips for more information.
Project #1: How Permanent Magnet Strength Varies with Temperature
Magnets are used worldwide (and in space) in nearly every industry. Their widespread use means they need to function predictably in extreme conditions, including significant heat and cold. The purpose of Project #1 is to observe, study, and understand magnets under extreme temperatures. Scientists define the temperature of something as a measure of random atom or molecule movement. In any object, even solid metal, the atoms are vibrating and moving. When cold, they move less. When warm, they move more. The question your child would pose to their class is: “Does an increase in temperature affect the alignment of magnetic domains, impacting a magnet’s overall strength?” While you won’t necessarily be able to test the Curie temperature (the temperature at which a metal can no longer be magnetized) because it is too hot, you can study and observe a more reasonable range. For example, you can use your freezer, which gets down to about -20°C, and a boiling pot of water, which gets to roughly +100°C.Materials & Goal
You will need the following items and materials to complete this science project:- 4" x 2" x 1/2" ceramic ring magnet
- Digital scale (measures in 0.1 g increments)
- Metal paper clips
- Thermometer
- Plastic tongs
- Heat resistant gloves or over-the-hand oven mitts
- Small container
- Flat surface
- Freezer
- Ice cubes
- Large plastic bowl
- Water
- Stove or hot plate
- Non-ferromagnetic pot
- Test your magnet’s strength at four temperatures
- -20°C (the temperature of your freezer)
- 0°C (the temperature of a water-ice bath)
- Approximately 20°C (room temperature)
- 100 °C (the temperature of boiling water)
4 Steps to Measure Magnet Strength
The metric of strength is how many paper clips the magnet can hold, measuring their total mass in grams (g). Before you begin your experiment, measure your magnet’s strength:- To measure strength (at room temperature), create a pile of paper clips on a flat surface. It should be an inch wider than your magnet on each side; make sure the top of the pile is flat.
- Wearing your gloves, hold the magnet over the pile; slowly lower it until it rests in the center of the pile.
- Slowly remove the magnet.
- Zero out your scale to indicate 0g for your small container; remove all the paper clips and put them in the container; weigh the clips; record the results.
- Measure the magnet’s strength a few times. Statistical fluctuations are normal; look for and eliminate ways you might be causing variations.
Test Strength at Different Temperatures
1. Freezer Test
- Put the magnet in a freezer for 30 minutes; put the thermometer in the freezer.
- Take the magnet out and measure its strength with paper clips as described above; return it to the freezer for 10 minutes.
- Repeat these steps several times; record your findings for five trials.
- Record the temperature in the freezer as recorded by the thermometer.
2. Ice-Water Test (0°C)
- Pour water and ice cubes into a plastic bowl; fully submerge the magnet in the bowl; leave it there for about 20 minutes (add ice if needed to remain at 0°C).
- Measure the magnet's strength several times; record your findings for five trials.
- Record the temperature in the water as recorded by the thermometer.
3. Room Temperature
- Allow the magnet and thermometer to sit at room temperature for 30 minutes.
- Measure the magnet’s strength several times; record your findings for five trials.
- Using your thermometer, measure room temperature; record.
4. Boiling Water Test
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Bring water on the stove to a soft boil; put your magnet into the water using tongs; leave it in for at least 20 minutes.
- Using tongs to remove the magnet, measure and record the magnet’s strength for five trials; keep the water at a soft boil.
- Use the thermometer to measure the water’s temperature; record.