問題一覧
1
The region where free electrons and said to be present
Conduction band
2
A unit of energy equal to the energy gained by an electron in passing from a point of low potential to a point one volt higher in potential
Electron volt
3
the magnitude of the induced EMF is PROPORTIONAL to the RELATIVE RATE OF CHANGE of flux
FARADAYS 2nd LAW
4
A unit of area, equal to the area of a circle with a diameter of one mil
Circular Mil (cmil)
5
the property of a device/material to ATTRACT bodies of iron and other magnetic materials
MaAGNETISM
6
relative permeability is VERY MUCH greater than 1
FERROMAGNETIC
7
2 Types of Artificial Magnet
PERMANENT AND TEMPORARY
8
Electrons occupying inner shell
Core electrons
9
EMF is INDUCED WHENEVER a conductor cuts magnetic flux
FARADAY 1st LAW
10
VERY STRONG attractive effect
FERROMAGNETIC
11
1C =
6.25x10^18e 3x10^9statc 1statc=1esu
12
the magnetic force that TENDS TO SETUP magnetic flux
MAGNETOMOTIVE FORCE (mmf)
13
The size of the force of attraction or repulsion between two charges is DIRECTLY PROPORTIONAL to the value of each charge
Coulombs 1st law
14
Opposite of RETENTIVITY
COERCIVITY
15
nucleus are said to be BROKEN INTO SMALLER PARTICLES
QUARKS
16
the DELAYED REACTION of the magnetization of a ferromagnetic material, with the change of of the magnetizing force
MAGNETIC HYSTERESIS
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relative permeability is SLIGHTLY LESS THAN 1
DIAMAGNETIC
18
force required to COUNTER RETENTIVITY and ELIMATE RESIDUAL MAGNETISM
COERCIVE FORCE
19
a measure of the ability of MAGNETIC CIRCUIT TO PERMIT SETTING UP FLUX
Permeance
20
The size of the force of attraction or repulsion between two charges varies INVERSELY as the square of the distance between two charges
Coulombs 2nd law
21
It is the process by which an atom or molecule acquires a negative or positive charge by gaining or losing electrons
Ionization
22
The energy difference between the valence band and conduction band
Energy gap
23
1 At =
1.257 Gb
24
the OPPOSITION OFFERED in a magnetic circuit to the flow of magnetic flux
RELUCTANCE
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The region where the valence shell and valence electrons are occupying
Valence band
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Electrons that escaped the valence shell after GAINING enough energy
Free electrons
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magnetism left AFTER THE REMOVAL of magnetizing force
Residual Magnetism / REMANENCE/ REMANANT MAGNETIZATION
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The SPACE AROUND charged bodies in which their influent is felt
Electric Field / Dielectric Field
29
It represents the SUM OF PROTONS AND NEUTRONS in the nucleus of an atom
Mass number
30
states that the magnitude of the EMF induced in a circuit is PROPORTIONAL TO THE RATE OF CHANGE of the magnetic flux that cuts across it
FARADAY LAW
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a magnetic field ALWAYS TENDS to arrange itself so that the GREATEST NUMBER of lines of force are created
Magnetism Second Law
32
1Wb= ?
10^8 Mx
33
1mil =
0.001 inch
34
if a normal right hand thread screw is screwed along the conductor in the DIRECTION OF THE CURRENT, the DIRECTION OF ROTATION of the screw is in the DIRECION OF MAGNETIC FIELD
SCREW RULE
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produce by EXPOSING a magnetic material into magnetizing force.
ARTIFICIAL MAGNETS
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At a that is not for T1
1/ l t l + T
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relative permeability is SLIGHTLY greater than 1
PARAMAGNETIC
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in electromagnetic induction, the current setup by the induced voltage TENDS TO CREATE FLUX whose direction opposes any change in the EXISTING FLUX
LENZ LAW
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1MCM = 1kcmil =?
1000cmil
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the energ needed to move a charge AGAINST ELECTRIC FIELD
Electric Potential Energy (U)
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Electrically unbalanced atom
Ion
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ability of material to RETAIN magnetism
RETENTIVITY
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Electric charges that are not moving
Electrostatics
44
VERY LOW "REPELLANT" EFFECT
DIAMAGNETIC
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the INTENSITY of magnetic field needed to REDUCE magnetization of a ferromagnetic material to ZERO
COERCIVITY
46
are natural material exhibiting PERMANENT MAGNETISM such as lodestone or Magnetite
Natural Magnets
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if the coil is GRIPPED with the right hand, with the fingers pointing in the direction of the current, then the thumb outstretched parallel to the axis of the solenoid, points in the direction of the magnetic field inside the solenoid
GRIP RULE
48
the concept whereby a SMALL VOLTAGE is generated by a conductor (PERPENDICULAR/90 degrees) with a current in an EXTERNAL MAGNETIC FIELD
HALL EFFECT
49
Common Materials: Bismuth, Antimony, Copper, Silver, Gold, Zinc, and Mercury
DIAMAGNETIC
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the MMF PER UNIT OF LENGTH at any given point in a magnetic circuit
MAGNETIC FIELD INTENSITY(H)
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the PRODUCTION of electric current, potential or voltage due to MAGNETISM
ELECTROMAGNETIC INDUCTION
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Positive ion, it is an atom that loses some of its valance electrons
Cation
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the total number of MAGNETIC LINES of force leaving or entering the pole of magnet
MAGNETIC FLUX
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the force is produced due to the applied electric current in the COIL of N TURNS
MAGNETOMOTIVE FORCE (mmf)
55
HEAT PRODUCED due to DISTURBANCES in the alignment of the domains of a FERROMAGNETIC material causing energy to be expended in taking it through a cycle of magnetisation
HYSTERESIS LOSS
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Electrical force that moves the charge particles such as electrons
Electromotive force
57
Value of coulomb's constant
8.99x10^9 N m^2/c^2
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Orbits where electrons reside
Shells
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ability to ACCEPT, ALLOW or SETUP a magnetic field
PERMEABILITY
60
The quantity of energy needed to discharge an electron from the valence shell
Ionization energy
61
Electrons in the outer shell
Valence electrons
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VERY LOW attractive effect
PARAMAGNETIC
63
Any directional movement of electric charges
Current
64
1 T =?
10^4 G
65
Property of material to oppose or limit the flow of current
Resistance
66
Negative ion, is an atom that gains some valence electron
Anion
67
Like poles repel, Unlike poles attract
Magnetism 1st Law
68
Common Materials: Aluminum, Chronium, Manganese, Platinum, and Carbon
PARAMAGNETIC
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Magnetism due to electric charges that are MOVING such as the flow of electric current
ELECTROMAGNETISM
70
It represents the NUMBER OF PROTONS in the nucleus of an atom. It also determines the place of the element in periodic table
Atomic number
71
Common Materials : Iron, Nickel, Cobalt, ALNICO, permalloys, Ferrites, Magnetic Oxides
FERROMAGNETIC
72
1 A/m =
0.01257 Oe