Experiment on BH curve

1. To study Of B-H curve of
materials using CRO
By Achal, Amiet, Aditya

2. Content:
 Aim
 Apparatus
 Formula
 Theory
 Circuit diagram
 Result
 Application

3. Apparatus:
B-H curve cabinet, A.C step down
transformer , sample coil, CRO, BNC, patch
cords , tracing paper, graph sheets
Formula:-
(N1/N2)×(R2/R1)×(C2/AL)×Sv×SH× area of loop
Aim:
To study B-H curve Of materials by using CRO

4. Magnetism
 The spin motion of electrons and their
interaction with one another is what is
responsible for the origin of magnetism.
 The only difference is that some
materials are more magnetic than others.
The level of interactions between the
magnetic moments is what distinguishes
them.
It may come as a surprise to you, but
all matter is magnetic.

5. Diamagnetic Materials
 Diamagnetic materials usually get repelled from a
magnet. Technically, these solids create an induced
magnetic field in a direction opposite to an
externally applied magnetic force and are repelled
by the applied magnetic field.
 Examples: Mercury, water, copper, bismuth, and
gold
This phenomenon is just the opposite
behaviour exhibited by paramagnetic materials

6. Paramagnetic materials
 Paramagnetic materials are materials that tend to get
weakly magnetized in the direction of the magnetizing
field when placed in a magnetic field.
 Paramagnetic materials have a permanent dipole moment
or permanent magnetic moment. However, if we remove
the applied field the materials tend to lose the magnetism
 The magnetic condition of an atom having one or more
unpaired electrons is known as Para magnetism.
 Examples: Tungsten, Caesium, Aluminium, Lithium,
Magnesium and sodium

7. Ferromagnetic materials
 Ferromagnetism is caused in ferromagnets and the
ferromagnets need to have net angular momentum which
is obtained either through the orbital component of the
spin component.
 Ferromagnetism is a physical phenomenon (long-range
ordering), in which certain materials like iron strongly
attract each other. Ferromagnets occur in rare earth
materials and gadolinium. It is one of the common
phenomena that is encountered in life that is responsible
for magnetism in magnets.
 Examples: Iron, cobalt, nickel, etc.

8. Domain Theory
A magnetic domain is a region within a
magnetic material in which the
magnetization is in a uniform direction. This
means that the individual magnetic moments
of the atoms are aligned with one another
and they point in the same direction.

9. Paramagnetic
materials
Diamagnetic
Materials

10. Curie temperature
Curie point, also called Curie
Temperature, temperature at which
certain magnetic materials undergo a
sharp change in their magnetic properties.

11. Instrumentation
 The unit enable one to trace the B-H loop (hysteresis) of
ferromagnetic specimen using CRO.
 A measurement of area of loops to evolution of energy
loss in the specimen .
 The complete unit require CRO to perform the
experiment.
 It contains of electronic circuit focused in a cabinet one
specimen of transformer , stamping & another sample of
Ferrite ring is also applied.

12. Procedure
 Connect primary & secondary transformer specimen to
respective terminals.
 Adjust CRO to work on x-y mode.
 Connect terminal CRO (x) to x-input of CRO.
 Connect terminal CRO (y) to y-input of CRO.
 Connect terminal D-A, D-B,D-C one by one .
 Switch ON power supply of the unit force of the loop on
the trace paper & estimate the area of the loop.

13. CRO & B-H curve apparatus

14. Transformer core

15. Ferrite core

16. ExpectedResult:

17. A hysteresis loop (also known as a hysteresis curve) is a
four-quadrant graph that shows the relationship between
the induced magnetic flux density B and the magnetizing
force H. It is often referred to as the B-H loop.
Retentivity – The property of the magnetic material to
retain magnetism even in the absence of the magnetizing
field is known as retentivity.
Coercivity – The magnetizing field needed to demagnetize
the magnetic material completely is known as it’s coercivity.
Hysteresis loop

18. Application
 Magnetic tapes , hard disk & credit cards these
application hard magnet like iron are design a
memory is not easily erased.
 Soft magnets are used as core in electromagnets.
 Hysteresis motors are used for rotating gyroscope
rotators in internal navigation & control system.

19. Thank You!!