Explaining concepts like electromagnetism can be hard for learners of any age but there seems to be a sweet spot at around 3rd and 4th grade. These are the years that lower school science teacher Jenny Jones works with at the Hillbrook School. Jones has been tinkering with her units on the electromagnetic spectrum for the past few years. One of her new favorite projects is the bulb dissection day, followed by a few days of building and testing materials to make them light up using up to 40 volts of electricity. Kids know the light bulb was “invented” by Edison, but this knowing is the kind that stifles the joy of personal discovery. This project is a perfect example of how to put young learners in the shoes of an inventor and to taste that little bit of glory when something works!
“Students love to take things apart, especially things that previously were off limits, like light bulbs,” Jones reports, “Understanding the inner workings of a light bulb is a great addition to any electricity unit and rebuilding their own is the perfect assessment of their understanding of this concept.”
Jones led her class in a discussion about what the “essential” parts of a light bulb were that allowed light to form. Using this discussion students then had a mental model of what a basic light bulb design would consist of. Mrs. Jones explained what materials were available to them including several wire spools of different thickness and different metal type. For the insulators Jones provided clay, cork and plastic straws for design and testing.
This kind of building activity with such immediate testing returns is a joy for learners of all ages. Connecting the test wires to the support wires of the student designs can be tricky so using a ring stand, standing in a bucket of sand, with a cylinder shaped clamp works well as a stabilizer. This will protect you from a potential small fire, spark or smoke, and leaves your hands free to use the power supply. If your supply has a dial that allows you to slowly feed current, you can talk about the importance of voltage and getting a resistor like a bulb to do work for us. This is real engineering and there is a lot of science behind the successes and failures to dive into. Some failures are due to too much resistance, other to not enough. When a design causes a short circuit, be sure to have lots of extra fuses on hand to keep your power supply working.
All the students wanted to see what others had built and everyone gathered around for the testing of their prototypes which created learning opportunities during each testing. Students took this information and continued to improve their design and then tested it. This project could go on for days and the students were begging to come in at lunch/recess and any time possible to test their light bulbs. The documentation was in their journal and students were asked to add onto their drawings as they improved their lightbulb. Photos and videos were taken by adults.
Leave a Reply