PHYSICSPROJECT Submitted BY: SAURAV PANDEY CLASS: XII-A TO STUDY THE EFFECT OF TEMPERATURE ON MAGNETIC STRENGTH . 2013 Roll No :9185574 School :Balwantray Mehta Vidya Bhawan Certified to be the bonafide work is done by Master ___Saurav Pandey___ of class XIIA in the Physics Lab during the year 2012-2013.-: Certificate : Guided By :. Date :-20-01-2013 Submitted for Central Board of Secondary Education. Aradhna Goyal Class :XII – A Year :2012. Examination held in Physics lab at Balwantray Mehta Vidya Bhawan School EXAMINER Date :-_________ .Mrs. lab assistant and also to my classmates who helped me to carry out this project work successful and for their valuable advice and support . immense motivation .who guided me to the successful completion of this project. I extend my hearty thanks to Mrs. which I received from them time to time…. which has sustained my efforts at all the stages of this project work… I can’t forgot to offer my sincere thanks to Mr.Sunil.Aradhna Goyal. I take this opportunity to express my deep sense of gratitude for her invaluable guidance.K Tripathi. I sincerely appreciate this magnanimity by taking me into his fold for which I shall remain indebted to him. . Balwantray Mehta Vidya Bhawan School for his encouragement and for all the facilities that he provided for this project work.ACKNOWLEDGEMEN T I wish to express my deep gratitude and sincere thanks to the Principal.Mr. A. constant encouragement . Physics teacher. Material required 4-.Observation 7-.Objective 3-.Introduction 2-.Bibliography…… .Theory 5-.Procedure 6-.-: CONTENTS :1-.Conclusion 8-. with magnetic force decreasing as temperature increases. the stronger the magnetic force.OBJECTIVE THE OBJECTIVE OF THIS EXPERIMENT IS TO DETERMINE THE EFFECT OF TEMPERATURE ON THE STRENGTH OF A MAGNET. Graphically. Our independent variable is temperature. this will be calculated using the amount of paperclips that the magnet is able to collect at each measured temperature . HYPOTHESIS It is believed that the colder the magnet. Our dependent variable is magnetism. the results will resemble an exponential curve. MATERIAL REQUIRED • • • • • • • • • • Safety glasses 3-4 permanent bar magnets Tongs for magnet Ice Water Insulating container Three strong bowls Small pot Burner for heating water or oven Paper clips(1000) . but also the strength of the magnet (Cold magnet). A magnet of this nature can be created by exposing a piece of metal containing iron to a number of situations (i. Magnetic lines of force do not intersect one another. entertainment. magnets are used in manufacturing. These lines originate at the north pole of the magnet and continue to the south pole.INTRODUCTI ON Magnets are frequently used in daily life. cold temperature slows the movement (magnetic Field Strength and Low Temperatures). and as such the movement of the particles. The motion of negatively charged electrons in the magnet determines not only the polarity. security. These domains function as all atoms do. For example. Additionally. and they play a crucial role in the functioning of computers. on the other hand. The north pole is positive. In the 1800’s. paramagnetic objects are those that can become magnetic only when in the presence of an external magnetic field. Magnets are filled with magnetic lines of force . Some magnets. As the temperature of the magnet approaches . referred to as permanent. Even the earth itself is a magnet. Soft magnets. The higher the heat. Slower movement leads to more fixed directions in terms of the domains. repeatedly jarring the metal. Magnetism is created by the alignment of small domains within a specific set of metal.e. the greater the energy. The temperature at which this demagnetization occurs is called the “Curie point”. are those that lose their magnetic charge properties over time. A magnet is any object that produces a magnetic field . A magnetic field is the space surrounding a magnet in which magnetic force is exerted. thus the temperature affects the movement. hold their magnetism without an external electric current. Pier4re Curie discovered that there exists a temperature at which objects that were previously permanently magnetic lose this characteristic . In contrast. heating to high temperature). whereas "soft" materials have low coercivity. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials. which can be magnetized but do not tend to stay magnetized. which are also the ones that are strongly attracted to a magnet. and this threshold depends on coercivity of the respective material. These include iron. nickel. Materials that can be magnetized. Although ferromagnetic (and ferrimagnetic) materials are the only ones attracted to a magnet strongly enough to be commonly considered magnetic. "Hard" materials have high coercivity. Permanent magnets are made from "hard" ferromagnetic materials such as alnico and ferrite that are subjected to special processing in a powerful magnetic field during manufacture. A permanent magnet is an object made from a material that is magnetized and creates its own persistent magnetic field. all other substances respond weakly to a magnetic field. to align their internal microcrystalline structure. Ferromagnetic materials can be divided into magnetically "soft" materials like annealed iron. and magnetically "hard" materials. by one of several other types of magnetism. and some naturally occurring minerals such as lodestone. some alloys of rare earth metals. and attracts or repels other magnets. a certain magnetic field must be applied. . To demagnetize a saturated magnet. An everyday example is a refrigerator magnet used to hold notes on a refrigerator door.THEORY A magnet is a material or object that produces a magnetic field. such as iron. making them very hard to demagnetize. which do. cobalt. are called ferromagnetic (or ferrimagnetic). 8. Remove magnet and attached paperclips and place on scale. . 11. Weigh magnet and record. 2. 7. 3. 10. 12. 6.Set freezer to 5-Celsius degrees higher than previous temperature. Record temperature of magnet and grams attracted.Subtract the weight of the magnet from the weight of the magnet and the paperclips combined. Wait approximately 20 minutes for the magnet to reach the temperature of the freezer. Place magnet in bowl filled with paperclips. 4. (Note: freezer accuracy is dubious. Place magnet and freezer thermometer in freezer set to lowest temperature possible. Situate scale near bowl. Place paperclips in bowl. . Record temperature read by freezer thermometer.Repeat steps 4-12 until freezer and magnet have reached zero degrees Celsius. Use temperature read by freezer thermometer) 13. 9. Remove paperclips and place back in bowl.PROCEDURE Cold Process 1. 5. Place magnet in oven set to highest temperature possible. 10. 2. Record temperature of magnet and grams attracted. 7. Place magnet in bowl filled with paperclips. Remove paperclips and place back in bowl. 5. Allow magnet to rest for 5 minutes undisturbed. 11. Repeat steps 6-11 until magnet reaches room temperature. Situate scale near bowl. Place paperclips in the bowl. Weigh magnet and record. 6. Remove magnet and attached paperclips and place on scale. 9. 4. Subtract the weight of the magnet from the weight of the magnet and the paperclips combined. 12. 3. . Wait approximately 20 minutes for the magnet to reach the temperature of the oven.Hot Process 1. 8. OBSERVATION MAGNETS UNDER EXTREME HEAT Time after removal from oven (minutes) 0 Weight attracted (in grams) 200 5 200 10 240 20 210 25 230 30 220 35 206 40 204 45 200 50 185 . 3 275 -19.1 265 -15.7 245 -4.7 260 -6.MAGNETS UNDER EXTREME COLD Temperature (degree celsius) Weight attracted (in grams) -21.4 275 -18.7 200 0 225 .6 220 -1.3 270 -13. . the ferromagnetic material becomes paramagnetic. this balance is destabilized. and the total magnetization is zero. Ferromagnetism The way in which specific materials form permanent magnets or interact strongly with magnets. Even if you cool the magnet. the atoms slow down so the magnetic domains are aligned and. When exposed to extreme temperatures. once it has become demagnetized. it will . Excessive heat causes atoms to move more rapidly. when a magnet is exposed to extreme cold. too much heat can completely ruin a magnet. the spins aren’t aligned. Aluminum and oxygen are two examples of materials that are paramagnetic at room temperature. magnetic properties are then affected. in turn. In other words. While cold strengthens magnets. Curie Temperature Named for the French physicist Pierre Curie. the percentage of magnetic domains spinning in the same direction decreases. This lack of cohesion weakens the magnetic force and eventually demagnetizes it entirely.conclusion Magnetic materials should maintain a balance between temperature and magnetic domains (the atoms’ inclination to spin in a certain direction). As the atoms are sped up. strengthened. They are attracted to magnetic fields. Most everyday magnets are a product of ferromagnetism. however. disturbing the magnetic domains. That's because the atoms spin in random directions. heat can result in the loss of magnetic properties. At this temperature. the Curie Temperature is the temperature at which no magnetic domain can exist because the atoms are too frantic to maintain aligned spins. but they are not magnetized when the external field is removed. Paramagnetism A type of magnetism that occurs only in the presence of an external magnetic field. In contrast. com NCERT Physics book www.com www.com www.wikipedia.BIBLIOGRAPHY www.howmagnetswork.sciencebuddies.technopedia.com .icbse.com www.
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