Electric Exam: A Homemade Electrical Quiz Board

What You Want to Know
How does a homemade electric quiz board work?

What Do You Think Will Happen
In a homemade electric quiz board, the light bulb will light up when you touch the paper clips to:
    a. items that do not match
    b. items that match
    c. each other

Here's what you will need to make it:
  • lights from a string of Christmas tree lights
  • one or two C batteries
  • rubber bands (preferably 3.5" by .25")
  • electrical tape
  • tag board or heavy cardboard (approximately 7" x 10")
  • hole puncher
  • marker
  • aluminum foil
  • scissors
  • 2 paper clips

This photo shows the back of the quiz board. Notice how one strip of aluminum foil is completely covered before the next strip of foil is placed on the board.
This photo shows the finished quiz board. The black border that you see on the edge of the board is electrical tape. The border of electrical tape is not necessary. We added it because it made the quiz board look nice.
Electric Exam: A Homemade Electrical Quiz Board

Here's what you have to do:
1. First, use a piece of scratch paper to create 6 tricky math problems. The math problems should be simple to write, since they have to fit on the tag board, but not so simple to solve. You want the people who play your game to have a challenge!

2. Punch 6 holes in each vertical (long) side of a piece of tag board.

3. When you have decided on the 6 math problems and are confident that you have the correct solution to each problem, write the problems down one side of the tag board and write the answers down the other side of the tag board, next to the holes in the board. Be sure to mix up the questions and answers so that the answers are not on the same line as the questions. You are creating a puzzle, so make it tricky if you can.

4. Remove one light bulb from a string of miniature Christmas lights. Leave about 6 inches of wire on either side of the light bulb. Strip about 1 inch of insulation, which is the green plastic wire coating from each end of the wire. NOTE: This will be done for you before you arrive at Discovery.

5. On the back side of the board, connect the holes for two matching items using a strip of aluminum foil that is barely wider than the punched holes. Fold the foil so that the strip is thicker than just one layer of foil. The foil should show through the punched holes. With the foil in place behind the holes, carefully cover the entire strip with electrical tape. Do not leave any foil showing, or your game may not work properly.

6. Repeat step 5 for the other matching math problems.

7. Line up two batteries so that the positive terminal of one is touching the negative terminal of the other one. Wrap a rubber band around the two batteries the long way. Wrap a piece of tape around the batteries the short way where the ends of the batteries meet. The rubber bands will be on the inside of the tape.

8. Cut two pieces of foil 1 inch by 10 inches. Fold both of them in half the long way. Connect one piece of foil to each terminal of the battery by sliding the foil under the rubber bands.

9. Take one free end of the aluminum foil (the other end is attached to the battery now) and tape it to the wire from one end of the light bulb wire. Put the wire from the light bulb inside the folds of aluminum foil. Make sure the copper colored wire is touching the foil before you apply the tape.

10. Attach a paper clip to the other wire from the light bulb.

11.   Attach a second paper clip to the end of the remaining loose piece of foil. Use tape to secure it.

12. Test your electrical quiz board by touching one paper clip to a punched hole in one column and the other paper clip to the hole for the matching item in the other column.

13. When you are not playing with your quiz game, slide the aluminum foil from underneath the rubber bands near the batteries. This way, you can be sure that you won't waste the batteries. Reconnect the foil to the batteries when you want to play the game.

Electric Exam: A Homemade Quiz Board Your Name: _____________________________
Circuit A closed path capable of being followed by an electric current.
Current A steady, smooth, onward movement; A flow of electric charge.
Charge To energize by passing an electrical current through.
Conductor Something that is capable of transmitting electricity or heat.
Insulation The act of separating one thing from others by nonconductors, so as to prevent the transfer of electricity or heat.
Transmit To send from one thing to another.

What's Going On Here
The light bulb lights up when you have a complete, or closed, circuit. The is the case when you have selected a matched pair on the quiz board. If you select the wrong match, the path for the electricity is not complete, since the foil does not connect the boles on an incorrect match. So when you make the wrong match, the light bulb will not light up.

What Happened???
What happened when you matched two items correctly on the quiz board?

What happened when you matched two items incorrectly on the quiz board?

What It Means
What do your observations tell you about how electricity flows in a homemade electric quiz board circuit when you match two items correctly?

What do your observations tell you about how electricity flows in a homemade electric quiz board circuit when you match two items incorrectly?

From what you observed about how electricity flows in a circuit, what do you think would happen if you did not completely cover one of the aluminum foil strips on the quiz board with electrical tape?

List all the materials you used to make the quiz board that are conductors (conductors allow electricity to flow through them).