Magnetism

Question 1

alternative to magnetic induction for the fundamental magnetic field vector B

Answer 1

Magnetic Flux Density

Question 2

Wrote the earliest known experimental physics

Answer 2

Petrus Peregrinus (Willian Gilbert)

Question 3

The book written by W. GIlbert about the earliest known treatise of fundamental physics

Answer 3

de Magnete

Question 4

the reason why magnetic compasses did not point exactly to the geographical north

Answer 4

Magnetic Declination

Question 5

Geomagnetism and Paleomagnetism declination was the principal cause of error in map making.

Answer 5

Mercator

Question 6

Theorized The magnetized needle assumed a non horizontal attitude in the vertical plane

Answer 6

Georg Hartmann

Question 7

The deviation from the horizontal

Answer 7

Magnetic inclination

Question 8

continuous drift in the intensity and direction of the field. reflects changes in the earth’s interior over time

Answer 8

Secular Variation

Question 9

observed that magnetic needle is deflected at right angles to conductor carrying a current; electrical current produces magnetic force

Answer 9

Hans Christian Oersted

Question 10

proposed that electrical currents were responsible for the existence of magnetism in iron objects

Answer 10

Ampere

Question 11

Magneto electric induction

Answer 11

M. Faraday

Question 12

static magnetism was carried by magnetic charges

Answer 12

C. F. Gauss

Question 13

Magnetic Declination: compass points to the east

Answer 13

positive

Question 14

Magnetic Declination: compass points to the east

Answer 14

negative

Question 15

declination value is constant

Answer 15

isogonic lines

Question 16

lines along declination value is zero

Answer 16

Agonic Lines

Question 17

Angle formed between the earth’s surface and planet’s magnetic lines

Answer 17

Magnetic Declination

Question 18

Mag Inclination: Upward

Answer 18

-

Question 19

Mag inclination downward

Answer 19

+

Question 20

property of material that are repelled by a magnetic field

Answer 20

Diamagnetic

Question 21

Diamagnetic Minerals

Answer 21

Quartz, Calcite

Question 22

Parallel to the magnetic field but weak attraction, susceptibility is reversible, small and positive.

Answer 22

Paramagnetism

Question 23

weakly attracted to magnetic field

Answer 23

Paramagnetism

Question 24

Magnetization of a paramagnetic material is directly proportional to the applied magnetic field (B) and inversly proportional to the Temperature (T) in Kelvin

Answer 24

Curie’s Law

Question 25

Examples of Paramagnetic Minerals

Answer 25

Clay minerals, chlorite, amphibole, px, olivine

Question 26

becomes magnetized and remains magnetized

Answer 26

Ferromagnetism

Question 27

Residual magnetization is called

Answer 27

Remanence (Isothermal Remanent Magnetization)

Question 28

When a ferromagnetic material is heated, its spontsnrous magnetization dissapears at ______

Answer 28

Curie Temp

Question 29

Mag moments align antiparallel to each other. This alignment leads to cancellation of the magnetic moments

Answer 29

Antiferromagnetism

Question 30

Mineral: Antiferromagnetism

Answer 30

llmenite

Question 31

temp at which an antiferromagnetic material undergoes a phase transition from an ordered state (A-Ferromagntism) to disordered state (Paramagnetic State)

Answer 31

Neel Temperature

Question 32

Crystals contains defects, vacancies, or impurites

Answer 32

Parasitic Ferromagnetism

Question 33

Example of parasitic ferromagnetism mineral

Answer 33

hematite

Question 34

Antiparallel and unequal in magnitude. Net magnetic moment smaller than that of ferromagnetic material

Answer 34

Ferrimagnetism

Question 35

Mineral: Ferrimagnetism

Answer 35

Magnetite

Question 36

Magnetic behavior is not uniform in all directions but depends on the orientation with respect to a preferred axis.

Answer 36

Magnetic Anisotropy

Question 37

Matrix minerals are mainly composed of

Answer 37

Silicates and Carbonates

Question 38

Silicates and Carbonates exhibits what magnetism

Answer 38

Diamagnetic

Question 39

Secondary minerals

Answer 39

CLay minerals, paramagnetic

Question 40

Magnetic property of rock is determined by_________

Answer 40

concentration of ferrimagnetic minerals

Question 41

The most important magnetic minerals and ar naturally occurring ferrites

Answer 41

Iron-titanium oxides

Question 42

low-temperature oxidation of titanomagnetite

Answer 42

Titanomaghemite

Question 43

T or F: Hematite in a higher state of oxidation than wustite

Answer 43

True

Question 44

Close-packed lattice of oxygen ions, in which some of the interstitial spaces are occupied by regular arrays of ferrous (Fe2+) and ferric (Fe3+) iron ions and titanium (Ti4+) ions

Answer 44

iron–titanium oxides

Question 45

When there's more titanium (x) in these minerals on the he Titanomagnetite Series, cell size _____, curie temperature ______.

Answer 45

Increases, decreases

Question 46

referred to as “hemoilmenite,” “hematite-ilmenite” or “ilmenohematite have the general formula Fe2–xTixO3 where compositional parameter x has the same implications for the titanium content of the unit cell

Answer 46

Titanohematite Series

Question 47

Third series but quite rare and are of minor importance in rock magnetism. paramagnetic at room temperature

Answer 47

Pseudobrookite

Question 48

on Neel Temperature antiferromagnetism disappears is around ______

Answer 48

320 C

Question 49

As Ti content increases, spontaneous magnetization________

Answer 49

decreases

Question 50

Which of the following minerals have the lowest Curie temperature? a. hematite b. goethite c. maghemite d. magnetite

Answer 50

C. Maghemite

Question 51

A remanence acquired at or close to the time of formation of the rock is called a

Answer 51

Primary Magnetization

Question 52

a remanence acquired at a later time is called a

Answer 52

Secondary Magnetization

Question 53

The most important type of remanent magnetization in igneous

Answer 53

thermoremanent magnetization (TRM).

Question 54

Occurs when rock cools below Curie temperature of ferrimagnetic minerals

Answer 54

Thermoremanent magnetization (TRM)

Question 55

Acquired during settling through still water Particles align with ambient magnetic field similar to a compass needle

Answer 55

Sedimentary remanent magnetization

Question 56

T or F : TRM is a very unstable magnetization which can exist unchanged for long intervals of geological time.

Answer 56

False

Question 57

may be caused by chemical change of the rock during diagenesis or weathering, or by sampling and laboratory procedures.

Answer 57

Secondary remanences

Question 58

is formed when the magnetic minerals in a rock suffer chemical alteration or when new minerals form authigenically.

Answer 58

Chemical remanent magnetization

Question 59

induced in a rock sample by placing it in a magnetic field at constant temperature.

Answer 59

Isothermal remanent magnetization (IRM)

Question 60

arises when a material undergoes mechanical deformation while in a magnetic field. The process of deformation may result from hydrostatic pressure, or directed tectonic stress.

Answer 60

Piezoremanent magnetization (PRM)

Question 61

shock remanent magnetization (SRM) observed in

Answer 61

Meteor impacts

Question 62

Piezoremanent magnetization (PRM) arises when a material undergoes mechanical deformation while in a magnetic field. The process of deformation may result from hydrostatic pressure, or directed tectonic stress.

Answer 62

Primary

Question 63

Secondary of Primary: Anhysteretic remanent magnetization (ARM) can be produced in a rock sample by placing it in a coil that carries an alternating magnetic field, whose amplitude is then slowly reduced to zero.

Answer 63

Secondary

Question 64

Primary or Secondary: Piezoremanent magnetization (PRM) arises when a material undergoes mechanical deformation while in a magnetic field.

Answer 64

Primary