bulletin board

Home

Chat

Blogs

Collection

Directory

Home : 2001 : January : 9

bulletin board
By Julianne

Ok, I think I've got a good one for you. Have each student draw a picture of his or her house and cut it out. Cut out a power station and put half the houses on one side of the board. Then use bell wire (telephone wire
or other thin wire will do fine) to connect each house to the next showing a simple circuit. Now cut out another power plant and use the remaining houses in two rows to show a parallel circuit. Do this by having each house link to and from a pair of parallel wires that come down from the power plant. You can see a simple diagram of this in any elementary electricity book. Students can

predict what would happen if someone cut a wire in each of the models. If you are handy you can build each of these models using a 6 volt lantern battery for the power source and lights cut from a set of christmas lights for the "houses". Cut each light away from the string leaving two 6" lengths of wire attached. Bare about 1/2 inch of wire at the end of each. Make the simple circuit by joining the lights together in a "holding hands" pattern with the battery at one position in the circle. If any one of the lights is removed the entire string goes dark. To make the parallel circuit you'll need a 1 foot piece of 2X4, 4 nails and about 4 feet of bare copper wire. Drive two nails about 2 inches apart at each end of the board. Cut the wire in half and run each piece between the nails on one side of the board making miniature telephone wires. Leave enough wire at one end to connect to the terminals of your 6 volt battery. Now carefully string your lights by hooking the bare part of one leg over one phone line and the other bare part over the other one. You should have a sort of ladder effect with the lights shining between the two parallel wires. You can show that you can remove any one light and the rest will stay lit.

Boy, I nearly didn't post this...it's so long. But I've used this experiment with kids over and over. It's a real crowd pleaser and they get a real feel for how electricity works.