DIE ELECTRICS AND MAGNETIC MATERIALS

                            DIE LECTRICS & MAGNETIC MATERIALS 

  

1. WHAT IS MAGNETIC SUSCEPTIBILITY ?

A)  The magnetic susceptibility Is defined as the Ratio of the Magnetisation Produced In a sample To the magnetic field strength.  has no Units.

 =                                                                        M = Magnetisation                                          H = Magnetic field strength

2. What is magnetic permeability ?

A)   The magnetic permeability µ is a measure of the amount of magnetic lines of forces penetrating through a material it is defined as the ratio of the magnetic flux density                 (or)

            Magnetic induction field strength B in the material to the applied magnetic   field intensity H

                         µ = B / H

3. Derive the relation between B,H,and M ?

  A) The magnetisation defines the auxiliary magnetic field H as

                          M

                       

4. Relation between  ?

 A)  -  Relative magnetic permeability

        – magnetic susceptibility

 Relation between :   and    

                  

            

5. What is diamagnetic, paramagnetic, ferromagnetic materials.

A) Dia magnetic : diamagnetic materials are slightly rippled by a magnetic      field end do not retain the magnetic properties when the external field is       removed

            Ex: organic materials,(Gold,Silver,Copper)

  para magnetic:  para magnetic materials are slightly attracted by a             magnetic field         and do not retain the magnetic properties when the      external field is       removed

            Ex: Alkali metals,transition metals (platinum,Aluminiu )

 

  Ferro magnetic:  ferromagnetic materials are strongly attracted by a             magnetic field end it’s have the magnetic properties when the external        field is removed

            Ex: trasition and rare earth metals (Iron,Nickel,Cobalt)

6. What is ferri magnetic materials ?

A) Net large magnetic moment exists in the direction of applied

            magnetic field        

 Ex: Ferrits   

7. What is hysteresis ?

A)     Hysteresis means yeah lag between input and output in a system upon a change in direction.

8.SOFT MAGNETIC : soft magnetic materials which can be easily magnetised end demagnetised are called soft magnetic materials

EX: Iran and silicon alloys, Nikhil iron alloys

9.Hard magnetic: hard magnetic materials which difficult to magnetised and demagnetised are called hard magnetic materials.

Ex: high carbon steel, cobalt steel.

9.  Applications Soft magnetic and hard magnetic materials.?

 A) soft magnetic materials:

1)    To  produce temporary magnets

2)    In the preparation of magnetic core materials

3)    Transformers ,motors ,amplifiers, magnetic switches.

10. Applications of Hard magnetic materials :

1)    To  produce permanent magnets.

2)     in loudspeakers, toys, measure metres, microphone, magnetic detectors