DEPENDENCE OF HIGH TEMPERATURE ON STRENGTH OF MAGNET
1. CERTIFICATE OF AUTHENCITY
This is to certify that Gaurav Sharma a student of class
XII has successfully completed project on
“DEPENDENCE OF HIGH TEMPERATURE ON
STRENGTH OF MAGNET” under the guidance of
(subject teacher).
The project is absolutely genuine and does not indulge in
plagiarism of any kind. The references taken in this project
have been declared at the end.
Signature (Subject teacher) Signature (Examiner)
2. ACKNOWLEDGEMENT
I feel proud to present my Investigatory project in Physics
on the topic “Dependence of high temperature on magnetic
strength”.
This project wouldn’t have been feasible without the proper
and rigorous guidance of my physics teacher who guided me
throughout this project in every possible way. An
investigatory project involves various difficult lab
experiments which have to be carried out by the student to
obtain the observations and conclude the report on a
meaningful note.
Rigorous hard work has been put in this project to ensure that it proves
to be the best. I hope that this project will prove to be a breeding ground
for the next generation of students and will guide them in every possible
way.
4. INTRODUCTION
A magnet is a material or objects that
Producesmagnetic field. This
magnetic field is invisible but is
responsiblefor the most notable
propertyof a magnet: a force that
Pulls on other ferromagnetic materials,
Such as iron, and attracts or repels
Other magnets.
A magnet is any object that producesa 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. repeatedlyjarring 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 surroundinga magnet in which
magnetic force is exerted. The motion of negatively charged
electronsin the magnet determines not only the polarity, but also
the strength of the magnet (Cold magnet). Magnets are filled
5. with magnetic lines of force. These lines originate at the north
pole of the magnet and continueto 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 temperatureaffects the movement. The higher the heat,
the greater the energy, and as such the movement of the
particles. In contrast, cold temperatureslows the movement
(magnetic Field Strength and Low Temperatures). Slower
movement leads to more fixed directions in terms of the
domains.
6. Theory
A magnet is a material or object that producesa magnetic field.
This magnetic field is invisible but is responsible for the most
notablepropertyof a magnet: a force that pullson other
ferromagnetic materials, such as iron, and attracts or repels other
magnets.
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 attractedto 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 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 them very hard to demagnetize. To
demagnetize a saturated magnet, a certain magnetic field must be
7. applied, and this threshold dependson 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.
8. Experiment
Aim: To determine the effect of increasing
temperature on strength of magnet
Apparatus:
• 1 permanent bar magnet
• Tongs for magnet
• Insulating container
• Three strong bowls
• Burner for heating or oven
• Paper clips(1000)
Theory: A magnet is a material or object that producesa
magnetic field. This magnetic field is invisible but is responsible
for the most notablepropertyof a magnet: a force that pullson
otherferromagnetic materials, such as iron, and attracts or repels
othermagnets.
9. Procedure:
1. Paperclips were placed in a bowl.
2. The magnet was weighed and recorded.
3. The magnet was placed in oven set to highest temperature
possible.
4. The magnet was allowed to reach the temperature of the oven.
5. The magnet was then placed in a bowl filled with paperclips.
6.The amount of paper clips attracted by the magnet was
weighed and recorded.
7.The steps 5 and 6 were repeated after setting the oven at
different temperatures and the quantity of paper clips attracted
was weighed.
10. OBSERVATION
The weight of pins attracted by the magnet at different
temperatures is:
Temperature (◦c) Weight (g) No of pins attracted
by magnet
200 2001 134
180 210 140
160 230 153
140 210 141
120 230 151
100 220 146
24 124 82
11. RESULT
The graph indicates that initially as the temperaturedecreases,
the number of pins attracted by the magnet also increases but up
to a certain limit.
Later as the temperaturedecreases, the number of pins attracted
by the magnet also decreases.
12. 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.
Heat can result in the loss of magnetic properties. In otherwords,
too much heat can completelyruin 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 the magnetic force and eventually
demagnetizes it entirely.
