One of the best science fair project ideas for students who are especially interested in the science and math of light travel is the Joly Photometer. This project allows students to use the inverse square law to measure the intensity of light. This may not be one of the best projects for lower grade students, as the project requires an understanding of some difficult math concepts.
To run this experiment, students will need to spend between $20 and $50. The project should take about a week, making it one of the most time-consuming science fair project ideas I’ve come across. Also, students may want to have a parent around to make sure the project is done safely.
Aim:
During this project, you’ll measure the light intensity of the light bulbs with your own handmade light meter.
Introduction:
Through this project, you will learn that different light sources have different powers to cast light in a room. All the light bulbs in your home may not have the same ability to emit light at the same distance. During this project, he will learn about the basic differences in how light bulbs work. In addition, she will build and use her own photometer.
Terms and concepts you will need to know:
You’ll learn a lot more about these terms and concepts throughout your experiment, but it’s a good idea to start with a basic understanding of them:
- Inverse Square Law (you will learn a lot about this law!)
- Incandescent light bulbs (you may already have some in your house)
- compact fluorescent bulbs
- Photometer (you will make your own)
Questions you will answer:
- What makes incandescent light bulbs work?
- Why do incandescent light bulbs die?
- What makes fluorescent bulbs work?
- Why do fluorescent light bulbs die?
- What is the bulb that lasts the longest?
- Which bulb produces light most efficiently?
Materials you will need:
You shouldn’t have to pay more than $50 for all of these supplies, but you’ll probably already find most of them in your home:
- a pound of paraffin wax
- a sharp knife
- Frustrate
- Cardboard box (small)
- Scissors
- Tape
- identical luminaires
- Tape measure (not a ruler)
- Various types of light bulbs
Procedure:
Follow these steps to successfully complete one of the best science fair project ideas to determine how light works differently with different bulbs:
- Cut a slab of wax in half. (Each box of wax should have four tiles.)
- Cut aluminum foil the same size as the tiles and place it between the 2 tiles.
- Create a cardboard box around the tiles. Use duct tape to hold it together.
- Make 3 windows in the sides of the cardboard box (one side will have no window). This is your photometer.
- Place the photometer straight between 2 lamps at the same distance and height. Make sure these light fixtures are the only sources of light in a room.
- With the bulbs on, move the light meter between the two bulbs until the wax is the same level of gloss on each side of the foil.
- To find the inverse square law, use the standard equation, found here.
- One of your bulbs should be your standard bulb. This bulb should be called I1. To find the intensity of the second light, make sure you divide the first light by the square of the distance and make it equal to the second light divided by the square of the distance so that both lights are the same meter distance away.
- Measure the distance from each bulb to your light meter (measure to the sheet).
- Use the equation to calculate the intensity of each bulb.
- To find out how efficient each bulb is, divide the relative intensity by the wattage of the bulb.
Again, this is one of my favorite science fair project ideas for students who enjoy math and physics. However, it can be difficult for those students who do not have a good understanding of the complicated equations. Science projects are meant to be fun, so have fun doing this project!
If you’re ready to get started with your own light intensity science project, your next step is to download a free copy of “Easy Steps for Award-Winning Science Fair Projects” from the link below right now!
