| Objective | | | | The alligator clips are to be attached to the terminals |
| You will be making an electromagnet using coils of | | | | of the battery. Use a shallow tray to hold the paper |
| wire. The aim of such science fair experiments is to | | | | clips (washers). |
| test how strong electromagnets can be. You will also | | | | Procedure |
| determine how the magnetic field strength is affected | | | | Begin with the core material with 100 turns of coil. |
| by the number of times the wire is wrapped around | | | | |
| while making the magnet. | | | | 1. Connect the alligator clips to the battery and hold the |
| Introduction | | | | coil of the electromagnet parallel to the tray, touching |
| A magnetic field is produced when a current flows | | | | the paperclips (washers) with the coil to pick them up. |
| through a wire. The same can be proved in science | | | | Move the coil out of the container and disconnect the |
| fair experiments by using a magnetic compass. Since | | | | battery. Now count how many paperclips were |
| a single wire has a comparatively weak magnetic field, | | | | attached to the coil and write down the number in a |
| the wire can be coiled to observe that the magnetic | | | | table. Repeat the same procedure 4 times more and |
| field strength increases with each added coil. | | | | calculate the average of all 5 readings and write it |
| You will find out how the magnetic field strength varies | | | | down in the table. |
| when the coil turns are increased. You will also find out | | | | 2. Now keep the coil of the electromagnet |
| how the coil should be oriented (parallel or | | | | perpendicular, touching the paperclips (washers) with |
| perpendicular) in order to be effective. | | | | the coil. Move the coil out of the container and |
| Material | | | | disconnect the battery. Now count how many |
| A 6V battery, alligator clips, magnetic wire, masking | | | | paperclips were attached to the coil and write down |
| tape, paper clips (one box) or 200 steel washers (1 cm | | | | the number in the table. Repeat the same procedure 4 |
| diameter) and three core material pieces of equal | | | | times more and calculate the average of the 5 |
| length such as iron nails or iron bolts or pieces of iron | | | | readings and write it down in the table. |
| pipe. | | | | 3. Next, take the coil with 200 turns and repeat steps 1 |
| Preparation | | | | and 2. |
| Three different electromagnets are to be made using | | | | 4. Then proceed with the coil with 500 turns and |
| core material of equal lengths. Now wrap the magnetic | | | | repeat steps 1 and 2. |
| wire neatly around each piece of core material, but let | | | | Make sure you record your findings without fail. Your |
| the number of turnings be different for each piece. For | | | | table will consist of a whole bunch of numbers. Graphs |
| example, one piece will be wrapped with 100 turns, the | | | | are very important during science fair experiments. So |
| second with 200 turns and the third with 500 turns. | | | | plot a graph showing the results for each orientation. |
| Keep the coiled wire in place at both ends by attaching | | | | The X-axis should reflect the number of coils and the |
| tape and leave at least 5 to 6 cm of extra wire for | | | | Y-axis should reflect how many paperclips (washers) |
| being connected to the battery. Using your utility knife, | | | | were attached to the electromagnet. |
| carefully remove the insulation of the free ends of the | | | | When you look at the graph you may be amazed that |
| magnetic wire and expose 1 cm of copper wire. | | | | all your efforts have been displayed by curved lines, |
| The free ends are to be connected to alligator clips | | | | which speak better than numbers. |
| which are always used in science fair experiments. | | | | |