Science for kids: Parallel vs Series Circuits

It has been awhile since I last sat down to type, but hopefully I can get back to my rambling.   We are finally getting settled down into a new home and I can start looking at a computer more than boxes!  What a good feeling!

We are heading into Christmas and the holiday period.  So maybe you have some time off work with your  kids or just to be a kid yourself. This is an easy project I did with the scouts a couple weeks ago for one of the Adventures in Science requirements.  The boys had to understand the difference between a Series and Parallel circuit and build each circuit.

There is a very easy way to build these circuits and understand the differences using the following supplies:

1. 2 pieces of paper
2.  Glue and Scissors
3.  Aluminium foil
4.  9 V battery
5. 2 small wattage bulbs:  I used a 6 W indicator bulb, but make sure they are only 12 V bulbs and not      120 V bulbs

Have you been putting up lights on a Christmas tree and one light goes out followed by all the lights going out?  This is a fun project because it will be easy for the kids to grasp why that happens.

Here are the circuits  my son made.  Just cut the aluminum foil into strips and glue them down on the paper.   The foil should be making very good contact with other piece of foil in places where you are connecting pieces so don't use too much glue.   For both the series and the parallel circuit leave a small gap at the top for the 9 V battery.    These circuits are set up to light 2 bulbs at a time.  The pictures below just show 1 bulb lighting up because you need a second person to hold the other bulb and I was being lazy.  .

The series circuit is how many Christmas lights are set up.  Looking at the pictures below you can see that if one light is removed you break the circuit which makes all the lights go out.  Using one light at each of the 2 gaps will make both lights work, but remove one light and they both go out.

The Parallel circuit is better because the circuit is still complete even when one light is removed. The top gap is again for the battery.  Then one light is used for each of the two gaps.  Removing one light will not affect the other light.

In order to make the lights work you need to make a strand of aluminum foil.  The socket part of the light should be wrapped tightly.  The bottom of the light should make contact with the circuit aluminum foil and the opposite end of the foil wrapped around the light should span the gap of the circuit you created and touch the aluminum foil.

To get light, make sure the battery is on the foil where you made a small gap at the top of the circuit.  With the light wrapped with a strand of foil place the light firmly on one side of a gap.  The other end of the strand attached to the light should cross the gap and make contact with the foil.  You can place another bulb at the bottom of the circuit to light two lights at a time.  Play around with removing either light.

The series can be set up the same way. In the picture below I added a "switch" instead of a second light by placing a small piece of foil across the second gap.  Remove lights or the switch to see what happens.

Have fun playing with electricity in a safe manner.  Once you place the battery down on the foil, it will start discharging and can become pretty hot. Just watch how hot it gets and don't leave it discharging too long. It will run the battery down pretty quickly as well.