Study of B-H curve by using CRO

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. Expected Result:

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!!