The Effects of Temperature on Magnetic Strength Joseph Gault Grade 9 February 2, 2008 Pittsburgh Central Catholic High School

Types of Magnets Ceramic – composed of powdered iron oxide and strontium carbonate ceramic; it is the most common magnet because it is cheap and easy to produce Ticonal - alloy of titanium, cobalt, nickel, and aluminum; developed by Philips for loudspeakers

Types of Magnets (cont.) Injection molded - composite of various types of resin and magnetic powders, allowing parts of complex shapes to be manufactured by injection molding; generally lower in magnetic strength and they resemble plastics Electromagnet - a wire that has been coiled into one or more loops –electric current flows through the wire, causing a magnetic field to be generated –commonly used in electric motors, junkyard cranes, and medical equipment, such as an MRI machine

Uses of Magnets Common uses for magnets: VHS Tapes Audio Tapes Floppy Discs Hard Drives Credit Cards Televisions Speakers Microphones Compasses

Purpose The purpose of this experiment was to determine: –If the strength of a magnet would be altered when placed in temperature zones less than room temperature, and warmer than room temperature. –If the strength of the magnet would remain changed when the magnet returned to room temperature.

Null and Alternative Hypothesis Null: Temperature changes will not significantly affect the magnetic strength of the magnets. Alternative: The various temperature zones will significantly affect the magnets’ strengths.

Materials -80°C Freezer -20°C Freezer -4°C Refrigerator Room at 20°C 45°C Incubator 100° Drying Oven 30 Ceramic Magnets Extech True RMS Digital Multimeter Gauss Attachment Tongs Gloves HP 39GS Graphing Calculator

Procedure 1.30 magnets were labeled (1-5) for 6 different temperature zones. 2.The magnetic strength of each magnet was measured with a voltage meter, and converted to Gauss using the following equation: B = 1000*(V0-V1)/k. 3.The 5 magnets of each group were placed into the following environments: -80°C Freezer -20°C Freezer 4°C Refrigerator Room Temperature Incubator – 45° C Drying Oven – 100° C

Procedure (Cont.) 4.The temperature of each magnet was measured immediately after the magnets were removed from the environments. 5.The magnetic strength of each magnet was measured immediately after removal from the temperature zone. 6.Data was recorded. 7.The magnets were allowed to return to 20°C. 8.The magnetic strength of each magnet was measured. 9.Data was recorded.

Experiment Incubator 4°C4°C Drying Oven Room Temperature Recording the Magnet’s Strength

Results and Conclusions The north and south poles of the magnets in the 4° refrigerator and 100° drying oven were significantly affected by the variation in temperature when they were immediately removed from the temperature zone. The north and south poles of the magnets in the 45° incubator and 100° drying oven were significantly affected when the magnets returned to room temperature.

My null hypothesis, stating that the various temperature zones will not affect the magnets’ strengths, was supported by the magnets in the 4° and 100° temperature zones. The magnets below 4° were affected by the temperature changes. The magnets ranging from 20°C to 45°C were affected by the temperatures when immediately removed from the temperature zones. Results and Conclusions

Limitations and Extensions Two of the magnets stuck together. This prevented me from recording their strengths when they were taken out of the temperature zone. I was unable to record the strength of the magnets while they were in the varying temperature zones. I had to remove them to record their strengths, and they began to return to 20°C. In the future, I would apply colder and warmer temperatures to the magnets, and try different methods of heating and cooling the magnets, such as using dry ice, or boiling water.

Resources/Acknowledgements s/j1613.pdf How Things Work Volumes 1-4 Fundamentals of Physics They Feynman Lectures on Physics The New Way Things Work My father and my teacher for supervising my project My mother for proofing my project