Project Outline: KANCHAN Classes · Web viewThere are times when silence speaks so much more loudly than words of praise to only as good as be a little person, whose words do not

0 | P a g e

Project Outline: KANCHAN Classes

CERTIFICATE

There are times when silence speaks so much more loudly than words of praise to only as good as be a little person, whose words do not express, but only put a veneer over true feelings, which are of gratitude at a point of time.This to certify that Mr. XXX , Student of class-XII , (school name) has completed the project titled“EFFECT OF TEMPRATURE ON MAGNETS”

during the academic year 2014-15 towards partial fulfillment of credit for the Physics Practical evaluation, under my supervision.

(PGT Physics)

1 | P a g e


ACKNOWLEDGEMENT

I wish to express my deep gratitude and sincere thanks to the Principal, MEENA KULSHRESTHA, Kendriya Vidyalaya Vikas Puri School for her encouragement and for all the facilities that she provided for this project work. I sincerely appreciate this magnanimity by taking me into her fold for which I shall remain indebted to her. I extend my hearty thanks to my Physics teacher, who

2 | P a g e


guided me to the successful completion of this project.

CONTENT

1. Introduction2. Objective3. Material required4. Theory5. Procedure6. Observation7. Conclusion

3 | P a g e


8. Bibliography……

INTRODUCTIONMagnets are frequently used in daily life. For example, magnets are used in manufacturing, entertainment, security, and they play a crucial role in the functioning of computers. Even the earth itself is a magnet.

Some magnets, referred to as permanent, hold their magnetism without an external electric current.

4 | P a g e

2


A magnet of this nature can be created by exposing a piece of metal containing iron to a number of situations (i.e. repeatedly jarring the metal, heating to high temperature). Soft magnets, on the other hand, are those that lose their magnetic charge properties over time.

A magnetic field is the space surrounding a magnet in which magnetic force is exerted. The motion

of

5 | P a g e


negatively charged electrons in the magnet determines not only the polarity, but also the strength of the magnet (Cold magnet). Magnets are filled with magnetic lines of force. These lines originate at the north pole of the magnet and continue to the South Pole. The North Pole is positive. Magnetic lines of force do not intersect one another.

OBJECTIVEThe objective of this experiment is to determine the effect of temperature on the strength of a magnet.

6 | P a g e

4


HYPOTHESIS It is believed that the colder the magnet, the stronger the magnetic force. Graphically, the results will resemble an exponential curve, with magnetic force decreasing as temperature increases. Our independent variable is temperature. Our dependent variable is magnetism; this will be calculated using the amount of paperclips that the magnet is able to collect at each measured temperature.

MATERIAL REQUIRED

7 | P a g e

5


Safety glasses3-4 permanent bar magnetsTongs for magnetIceWaterInsulating containerThree strong bowlsSmall potBurner for heating water or ovenPaper clips(1000)

8 | P a g e


THEORY

A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, and attracts or repels other magnets.

9 | P a g e

6


A permanent magnet is an object made from a material that is magnetized and creates its own persistent magnetic field. An everyday example is a refrigerator magnet used to hold notes on a refrigerator door. Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called ferromagnetic (or ferrimagnetic). These include iron, nickel, cobalt, some alloys of rare earth metals, and some naturally occurring minerals

such as lodestone. Although ferromagnetic (and ferrimagnetic) materials are the only ones attracted

10 | P a g e

7


to a magnet strongly enough to be commonly considered magnetic, all other substances respond weakly to a magnetic field, by one of several other types of magnetism.Ferromagnetic materials can be divided into magnetically "soft" materials like annealed iron, which can be magnetized but do not tend to stay magnetized and magnetically "hard" materials, which do. 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, to align their internal microcrystalline structure, making

11 | P a g e

8


them very hard to demagnetize. To demagnetize a saturated magnet, a certain magnetic field must be applied, and this threshold depends on

coercivity of the respective material. "Hard" materials have high coercivity, whereas "soft" materials have low coercivity.The overall strength of a magnet is measured by its magnetic moment or, alternatively, the total magnetic flux it produces. The local strength of magnetism in a material is measured by its magnetization.

12 | P a g e


PROCEDURECold Process1. Place paperclips in bowl. 2. Situate scale near bowl. 3. Weigh magnet and record. 4. Place magnet and freezer thermometer in freezer set to lowest temperature possible. 5. Wait approximately 20 minutes for the magnet to reach the temperature of the freezer.

13 | P a g e

9


6. Record temperature read by freezer thermometer. 7. Place magnet in bowl filled with paperclips. 8. Remove magnet and attached paperclips and place on scale. 9. Record temperature of magnet and grams attracted. 10. Subtract the weight of the

magnet from the weight of the magnet and the paperclips combined.

11. Remove paperclips and place back in bowl. 12. Set freezer to 5-Celsius degrees

higher than previous temperature.

14 | P a g e

10


(Note: freezer accuracy is dubious. Use temperature read by freezer thermometer) 13. Repeat steps 4-12 until freezer

and magnet have reached zero degrees

Celsius.

Hot Process1. Place paperclips in the bowl. 2. Situate scale near bowl. 3. Weigh magnet and record. 4. Place magnet in oven set to highest temperature possible.

15 | P a g e

11


5. Wait approximately 20 minutes for the magnet to reach the temperature of the oven. 6. Place magnet in bowl filled with paperclips. 7. Remove magnet and attached paperclips and place on scale. 8. Record temperature of magnet and grams attracted.

9. Subtract the weight of the magnet from the weight of the magnet and the paperclips combined. 10. Remove paperclips and place back in bowl. 11. Allow magnet to rest for 5 minutes undisturbed.

16 | P a g e

12


12. Repeat steps 6-11 until magnet reaches room temperature.

OBSERVATION Magnet under extreme heat

Time after removal from oven (minutes)

Weight attracted (in grams)

0 200 5 200 10 240 20 210 25 230 30 220

17 | P a g e


35 206 40 204

Temperature Weight attracted

-21.3 275 -19.4 275 -18.1 265 -15.3 270 -13.7 260

18 | P a g e

Magnet under extreme cold1415


-6.7 245 -4.6 220 -1.7 200

19 | P a g e


CONCLUSION Magnetic materials should maintain a balance between temperature and magnetic domains (the atoms’ inclination to spin in a certain direction). When exposed to extreme temperatures, however, this balance is destabilized; magnetic properties are then affected. While cold strengthens magnets, heat can result in the loss of magnetic properties. In other words, too much heat can completely ruin a magnet. Excessive

20 | P a g e

16


heat causes atoms to move more rapidly, disturbing the magnetic domains. As the atoms are sped up, the percentage of magnetic domains spinning in the same direction decreases. This lack of cohesion weakens the magnetic force and eventually demagnetizes it entirely.FerromagnetismThe way in which specific materials form permanent magnets or interact strongly with magnets. Most everyday magnets are a product of ferromagnetism.ParamagnetismThey are attracted to magnetic fields, but they are not magnetized when the external field is removed. That's

21 | P a g e


because the atoms spin in random directions; the spins aren’t aligned, and the total magnetization is zero.Aluminum and oxygen are two examples of materials that are paramagnetic at room temperature.Curie temperatureNamed for the French physicist Pierre Curie, the Curie temperature is the temperature at which no magnetic domain can exist because the atoms are too frantic to maintain aligned spins. At this temperature, the ferromagnetic material becomes paramagnetic. Even if you cool the magnet, once it has become demagnetized, it will not become magnetized again. Different magnetic

22 | P a g e


materials have different Curie Temperatures, but the average is about 600 to 800 degrees Celsius.

BIBLIOGRAPHYwww.icbse.com www.sciencebuddies.com www.technopedia.com www.wikipedia.com NCERT Physics book www.howmagnetswork.com

23 | P a g e

19

20

Documents

Project Outline: KANCHAN Classes · Web viewThere are times when silence speaks so much more loudly than words of praise to only as good as be a little person, whose words do not