2. 2
ACKNOWLEDGEMENT
First of all I would like to thanks the almighty GOD for all his
blessings to do this project. I would like to express my deep
gratitude and sincere thanks to our administrator Fr. GIGI P
ABRAHAM and our principal Mrs. ANU GEORGE.
I would like to express my special thanks to our teachers
Prof .VARGHESE CHACKO Sir, MELVIN Sir and NAVEEN Sir for
their encouragement and the facilities provided to do this
investigatory project on magnetism and its effect on temperature.
And finally I can’t forget to offer my sincere thanks to our lab
assistant Mrs. OMANA, my parents and my friends who helped me
to carry out this project successfully and for their valuable advice
and support.
3. 3
INDEX
S. No. CONTENT PAGE NO.
1 Objective 5
2 Material Required 6
3 Introduction 7
4 Theory 9
5 Procedure 10
6 Observation 12
7 Result 14
8 Applications of
magnets
15
9 Conclusion 16
10 Bibliography 17
4. 4
OBJECTIVE
To determine the effect of temperature on the strength of a
magnet.
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.
6. 6
INTRODUCTION
Magnets 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 is a magnet.
A magnet is any object that produces a magnetic field. Some magnets,
referred to as permanent, hold their magnetism without an external
electric current. 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. Additionally, paramagnetic objects are those
that can become magnetic only when in the presence of an external
magnetic field.
A magnetic field is the space surrounding a magnet in which magnetic
force is exerted. The motion of 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.
Magnetism is created by the alignment of small domains within a
specific set of metal. These domains function as all atoms do, thus the
temperature affects the movements.
The higher the heat, the greater the energy, and as such the movement
of the particles. In contrast, cold temperature slows the movement
(magnetic field strength and low temperatures). Slower movement
leads to more fixed directions in terms of the domains.
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8. 8
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.
A permanent magnet is an object made from the 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
ferromagnetic). These include iron, nickel, cobalt, some alloys of rare
earth metals, and some naturally occurring minerals such as
loadstone. Although ferromagnetic ( and ferromagnetic) materials are
the only ones attracted 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 ten
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 them very hard to demagnetize. To
demagnetize a saturated magnet, a certain magnetic field must be
applied, and this threshold depends on 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 total strength
of magnetism in a material is measured by its magnetization.
9. 9
PROCEDURE
Cold process
1. Place paper clips in a bowl.
2. Situate scale near bowl.
3. Weigh magnet and record.
4. Place magnet and freeze thermometer in freezer to set
lowest temperature as possible.
5. Wait approximately 20 minutes for the magnet to reach
the temperature of the freezer.
6. Record temperature by freezer thermometer.
7. Place magnet in a bowl filled with paper clips.
8. Remove magnet and attach paper clips 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 paper clips combined.
11. Remove paper clips and place back in bowl.
12. Set freezer to 5‐celsius degrees higher than previous
temperature. (Note: freezer accuracy is dubious. Use
temperature read by freezer thermometer).
13. Repeat steps 4‐12 until freezer and magnet have reached
zero degree Celsius.
14. 14
APPLICATIONS OF MAGNETS
1. Computers and Electronics
Many computers use magnet to store data on hard
drives. The small speakers found in computers, televisions and
radios also use magnets, inside the speaker, a wire coil and
magnet converts electronic signals into sound vibrations.
2. Electric Power And Other Industries
Magnets in electric generators turn mechanical energy
into electricity. Industrial strength magnets lift car sized
chunks of metals.
3. Health And Medicine
MRIs use powerful magnetic fields to generate radio
signal from the body to create clear picture of organs. Magnet is
used for treating cancer by generating heat in the body which
kills the cancer cell.
4. In Home
Refrigerator magnets ,pocket compass ,dark magnetic strip on
the back of the credit cards ,vacuum cleaners ,blenders , phone
,toys all uses magnets.
15. 15
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 temperature, 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 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 magnetic force and eventually demagnetizes it
entirely.
In contrast, when a magnet is exposed to extreme cold, the atoms slow
down so the magnetic domains are aligned and, in turn, strengthened.
FERROMAGNETISM
The way in which specific materials form permanent magnets
or interact strongly with magnets. Most everyday magnets are a
product of ferromagnetism.
PARAMAGNETISM
A type of magnetism that occurs only in the presence of an
external magnetic field. They are attracted to magnetic fields,
but they are not magnetized when the external field is removed.
That is 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.
