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 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

Types of Magnets (cont.) 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 in Technology Common uses for magnets: Televisions Telephones Headphones Computers Compasses Medical equipment

Null and Alternative Hypothesis Null: The various temperature zones will not affect the magnets’ strengths. Neither the temperatures below nor above 20°C will make the magnets stronger or weaker. Alternative: The various temperature zones will affect the magnets’ strengths. Temperatures below 20°C will make the magnet stronger by causing the particles to move very close together. Temperatures above 20°C will make the magnet weaker by causing the particles to expand.

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.

Materials -80°C Freezer -20°C Freezer -4°C Refrigerator Room at Room Temperature 45°C Incubator 60° Drying Oven 30 Ceramic Magnets Extech True RMS Digital Multimeter Gauss Attachment Tongs Gloves HP 39GS Graphing Calculator

Procedure 1.35 magnets were labeled (1-5) for 7 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 ° C Drying Oven Room Temperature Recording the Magnet’s Strength

Magnetic Strength Group 1 – South Pole Temperature -80°C

Magnetic Strength Group 2 – South Pole Temperature -20° C

Magnetic Strength Group 3 – South Pole Temperature -4°C

Magnetic Strength Group 4 – South Pole Temperature 20° C

Magnetic Strength Group 5 – South Pole Temperature 45° C

Magnetic Strength Group 6 – South Pole Temperature 100° C

Magnetic Strength Group 1 – North Pole Temperature -80°C

Magnetic Strength Group 2 – North Pole Temperature -20°C

Magnetic Strength Group 3 – North Pole Temperature -4°C

Magnetic Strength Group 4 – North Pole Temperature 20°C

Magnetic Strength Group 5 – North Pole Temperature 45°C

Magnetic Strength Group 6 – North Pole Temperature 100°C

Percentage Change of Magnetic Strength - Group 1 Temperature -80°C Percent (%)

Percentage Change of Magnetic Strength - Group 2 Temperature -20°C Percent (%)

Percentage Change of Magnetic Strength - Group 3 Temperature -4°C Percent (%)

Percentage Change of Magnetic Strength - Group 4 Temperature 20°C Percent (%)

Percentage Change of Magnetic Strength - Group 5 Temperature 45°C Percent (%)

Percentage Change of Magnetic Strength - Group 6 Temperature 100°C Percent (%)

Results and Conclusions The north and south poles of the magnets were not affected by the variation in temperature. The north and south poles of the magnets were not affected when the magnets returned to room temperature. My hypothesis, stating that magnets would be affected by temperatures ranging from -80°C to 100°C, was incorrect. Magnets are not affected by temperatures ranging from -80°C to 100°C.

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. 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.