Shared Flashcard Set

Details

MSE Quiz 4
Quiz 4.. Engr. Rulloda - Mapua Institute of Technology
134
Engineering
Undergraduate 4
03/03/2012

Additional Engineering Flashcards

 


 

Cards

Term
Magnetic Forces
Definition
generated by moving electrically charged particles
Term
Magnetism
Definition
the phenomenon by which materials asset an attractive or repulsive force or influences on other material
Term
Magnetic Induction
Definition
represents the magnitude of the internal field strength within a substance that us subjected ti an H field.
Term
Tesla
Definition
weber per square meter (w/m^2)
Term
Magnetic field strength
Definition
the externally applied magnetic field (H)
Term
Permeability
Definition
a property of the specific medium through which H fields partes and in which B is measured
Term
Magnetic Susceptibility
Definition
measures the response of electrons to a magnetic field
Term
Diamagnetic Field
Definition
H=0
Term
Curie Temperature
Definition
temperature above which a ferromagnet becomes a paramagnet
Term
Neel Temperature
Definition
temperature above which antiferromagnet becomes a paramagnet
Term
Magnetic susceptibility
Definition
the proportionality constant between magnetization M and magnetic Field Strength M.
Term
magnetization
Definition
total magnetic moment per unit volume of material. A measure of the contribution to the magnetic flux by some material within an H field.
Term
Bohr magneton
Definition
The most fundamental magnetic moment which is of magnitude of 9.27x10^-24 A.m^2
Term
Diamagnetism
Definition
is a very weak form of magnetism that is nonpermanent and persists only while an external field is being applied
Term
Paramagnetism
Definition
A relatively weak form of magnetism that results from the independent alignment of atomic dipoles with an magnetic field. Results when the atomic dipoles that are free to rotate preferentially align,by rotation with an external field.
Term
Ferromagnetism
Definition
permanent magnetic moment in the absence of an external field, and manifest very large and permanent magnetization.
Term
Saturation Magnetization
Definition
the maximum possible magnetization
Term
antiferro magnetism
Definition
the alignment of the spin moments of neighboring atoms or ions in exactly opposite directions
Term
Ferrimagnetism
Definition
ceramics that exhibit permanent magnetization.
Term
curie temparature
Definition
temparature where in saturation magnetization diminishes gradually and then abruptly drops to zero
Term
domain
Definition
small-volume regions in which there is mutual alignment in the same direction of all magnetic dipole moments
Term
hysterisis
Definition
effect produced in which the magnetic induction field lags begin the applied H field or decreases at a lower rate
Term
remanence
Definition
the material remains magnetized in the absence of an external H field
Term
Coercivity
Definition
The applied magnetic field necessary to reduce to zero the magnetic flux density of a magnetized ferromagnetic or ferrimagnetic material
Term
Soft magnetic material
Definition
small are of loop (hysterisis); are used in devices that are subjected to alternating magnetic fields and in which energy must be low
Term
eddy currents
Definition
elecrtical currents that are induced in a magnetic material by a magnetic field that varies in magnitude and direction with time
Term
Hard magnetic material
Definition
large area of hysterisis; used in permanent magnets have a high resistance to demagnetization
Term
Critical Temparature
Definition
temparature at which material attain superconductivity
Term
Neisser effect
Definition
a phenomenon where in an applied magnetic field will be excluded from the body of material
Term
Capacitor
Definition
material that stores energy
Term
Capacitance
Definition
magnitude of charge stored or either plate divided by the applied voltage`
Term
Dielectric
Definition
electrically insulating,exhibit electric dipole structure
Term
dielectric constant (k)
Definition
ratio of the permittivity of a medium to that of a vacuum.
Term
Capacitance
Definition
coulomb/volt or Farad
Term
Dielectric displacement
Definition
magnitude of charge per unit area of capacitor plate
Term
Dielectric strength
Definition
magnitude of an electric field necessary to cause significant current passage through a dielectric material (breakdown).
Term
Polarization
Definition
process of dipole alignment
Term
Electronic polarization
Definition
result from the distortion of an atomic electron cloud by an electric field
Term
Ionic Polarization
Definition
result from the relative displacement of elecrically charged ions in response to an electric field
Term
Orientation polarization
Definition
found only in substance posses permanent dipole moment which results a rotation of the permanent moment into direction of applied field.
Term
Relaxation Frequency
Definition
reciprocal of minimum reorientation time for realignment of dipoles when e- field is reversed
Term
Dielectric loss
Definition
absorption of e- energy by a dielectric material subjected to an alternative current e- field (microwave)
Term
Dielectric Strength
Definition
breakdown strength
Term
FerroElectricity
Definition
dielectric material that exhibit spotaneous polarization in the absence of electric field
Term
Piezoelectricity
Definition
press electricity polarization is induced and electric field is established across a specimen by the application of external forces
Term
Capacitance
Definition
quantity of charge stored on either plate
Term
Capacitor
Definition
stores energy
Term
Polarization
Definition
the process of dipole alignment. The increase in charge density above that for a vacuum because of the presence of the dielectric
Term
Electronic polarization
Definition
it results from displacement of the center of the negative by charged electron cloud relative to the positive nucleus of an atom by electric field
Term
ionic polarization
Definition
occurs only in material that are ionic. An applied field acts to displace cations in are direction and anions in the opposite direction,which gives rise to the net dipole moment
Term
orientation polarization
Definition
is found only in substances that possess permanent dipole moments
Term
dielectric loss
Definition
the absorption of electrical energy by a dielectric material that is subjected to alternating field
Term
Dielectric strength
Definition
represents the magnitude of an electric field necessary to produce breakdown
Term
ferroelectrics
Definition
dielectric materials that exhibit spontaneous polarization-that is polarization in the absence of an electric field
Term
piezoelectricity
Definition
pressure electricity,polarization is induced and an electric field is established across a specimen by the application of external forces.
Term
Transducers
Definition
devices that convert electrical energy into mechanical strains and vice versa
Term
intrinsic semiconductors
Definition
are those in which the electrical behavior is based on the electronics structure inherent in the pure material
Term
extrinsic semiconductors
Definition
the electrical characteristics are dictated by impurity atoms
Term
Donor
Definition
donates single electron to the conduction band
Term
n-type extrinsic semiconductor
Definition
the number of electrons in the conduction band far exceeds the number of those in the valence band
Term
acceptor
Definition
capable of accepting an electron from the valence band, leaving behind a hole
Term
p-type
Definition
holes are present in much higher concentrations than electrons
Term
intrinsic temperature region
Definition
region where electron concentration increases above P content an aymptotitacally approaches the intrinsic curve as temperature increases
Term
charge carrier's mobilities
Definition
the ease with which electrons and holes are transported through the crystal
Term
Hall effect
Definition
is a result of the phenomenon where by a magnetic field applied perpendicular to the direction of motion of a charged particle exerts a force on the particle perpendicular to both magnetic field and the particle motion directions
Term
Diode
Definition
an electronic device that allows the current to flow in one direction
Term
p-n rectifying junction
Definition
is constructed from a single piece of semiconductor that is doped so as to be n-type on one side and p-type on the other
Term
Forward bias
Definition
the positive terminal may be connected to the p-side and the negative terminal to the n-side. The holes on the p-side and the electrons on the n-side are attracted to the junction
Term
Reverse bias
Definition
the negative terminal is connected to the p-side and the positive terminal is connected to the n-side. Both holes and electrons are rapidly drawn away from the junction.
Term
Breakdown
Definition
a phenomenon where in very abrupt increase in current occurr
Term
Transistors
Definition
serve as switching devices in computers for the processing and storage information
Term
Flash memory
Definition
a rapidly evolving information storage technology that uses semiconductor devices
Term
conducting polymers
Definition
polymers that have electrical conductivities on part with metallic conductors
Term
Dielectric material
Definition
one that B electrically insulating and exhibits or may be to exhibit an electric dipole structure
Term
Electric dipole
Definition
separation of positive and negative electrically charged entities on a molecular or atomic level
Term
Piezoelectric materials
Definition
used in transducers
Term
transducer
Definition
device that convert electrical energy to mechanical strains
Term
transducer
Definition
materials are titanates of barium and lead zirconate (Pb2O3) quartz
Term
transistors
Definition
for amplification of electrical signals
Term
donor impurities
Definition
excess electron
Term
acceptor impurities
Definition
excess holes
Term
permittivity
Definition
proportionality constant between the electric displacement and the elctric field
Term
ohm's law
Definition
relates the current I or time rate of charge passage to the applied voltage
Term
electrical conductivity
Definition
used to specify the electrical character of a material
Term
current density
Definition
the current per unit area
Term
electric field intensity
Definition
the voltage difference between two points divided by the distance separating them
Term
Metals
Definition
are good conductors typically having conductivities on the order of 10^7 (ohmmeter)^-1
Term
Insulators
Definition
materials with very low conductivities, ranging between 10^-10 and 10^-20
Term
Semiconductors
Definition
materials with intermediate conductivities,generally from 10^-6 to 10^4 (ohmmeter)^-1
Term
electric current
Definition
results from the motion of electrically charged paricles in repsonse to focus that act on them from an externally applied electric field
Term
ohm's law
Definition
relates the current I or time rate of charge passage to the applied voltage
Term
electrical conductivity
Definition
used to specify the electrical character of a material
Term
current density
Definition
the current per unit area
Term
electric field intensity
Definition
the voltage difference between two points divided by the distance separating them
Term
Metals
Definition
are good conductors typically having conductivities on the order of 10^7 (ohmmeter)^-1
Term
Insulators
Definition
materials with very low conductivities, ranging between 10^-10 and 10^-20
Term
Semiconductors
Definition
materials with intermediate conductivities,generally from 10^-6 to 10^4 (ohmmeter)^-1
Term
electric current
Definition
results from the motion of electrically charged paricles in repsonse to focus that act on them from an externally applied electric field
Term
ohm's law
Definition
relates the current I or time rate of charge passage to the applied voltage
Term
electrical conductivity
Definition
used to specify the electrical character of a material
Term
current density
Definition
the current per unit area
Term
electric field intensity
Definition
the voltage difference between two points divided by the distance separating them
Term
Metals
Definition
are good conductors typically having conductivities on the order of 10^7 (ohmmeter)^-1
Term
Insulators
Definition
materials with very low conductivities, ranging between 10^-10 and 10^-20
Term
Semiconductors
Definition
materials with intermediate conductivities,generally from 10^-6 to 10^4 (ohmmeter)^-1
Term
electric current
Definition
results from the motion of electrically charged paricles in repsonse to focus that act on them from an externally applied electric field
Term
ohm's law
Definition
relates the current I or time rate of charge passage to the applied voltage
Term
electrical conductivity
Definition
used to specify the electrical character of a material
Term
current density
Definition
the current per unit area
Term
electric field intensity
Definition
the voltage difference between two points divided by the distance separating them
Term
Metals
Definition
are good conductors typically having conductivities on the order of 10^7 (ohmmeter)^-1
Term
Insulators
Definition
materials with very low conductivities, ranging between 10^-10 and 10^-20
Term
Semiconductors
Definition
materials with intermediate conductivities,generally from 10^-6 to 10^4 (ohmmeter)^-1
Term
electric current
Definition
results from the motion of electrically charged paricles in repsonse to focus that act on them from an externally applied electric field
Term
electronic conduction
Definition
current arises from the flow of electrons within solid materials
Term
ionic conduction
Definition
net motion of charged ions produces a current
Term
electron energy band
Definition
this is formed when each atomic state split into a series of closely spaced electron states in the solid
Term
Fermi Energy
Definition
the energy corresponding to the highes filled state at 0K
Term
conduction band
Definition
conduction electrons are those that have been excited to states within this band
Term
band gap energy
Definition
for semiconductors and insulators, the energies that lie between the valence and conductions bands; for intrinsic materials, electrons are forbidden to have energies within this range.
Term
Hole
Definition
a vacant electron statein the valance band that behaves as a positive charge carrier in an electric field
Term
Free electrons
Definition
electrons with energies greater than Fermi energy accelerate in the presence of electric field that participate in the conduction process
Term
Scattering phenomenon
Definition
is manifested as a resistance to the passage of an electric current
Term
drift velocity
Definition
the average electron velocity in the direction of the force imposed ny applied field
Term
electron mobility
Definition
an indication of the frequency of scattering events
Term
Matthiessens's Rule
Definition
the total resistivity of a metal is the sum of the contributions from thermal vibrations,impurities and plastic deformation, that is the scattering mechanism act independently of one another
Term
electromagnetic radiation
Definition
considered to be wavelike consisting of electric and magnetic field components that are perpendicular to each other and also to the direction of propagation
Term
photons
Definition
groups or packets of energy
Term
radiation intensity
Definition
corresoponds to the energy being transmitted per unit of time across a unit area that is perpendicular to the direction of propagation
Term
Transparent
Definition
materials that are capable of transmitting light with relatively little absorption and reflection
Term
translucent
Definition
materials are those through which light is transmitted diffusely; that is; light is scattered within the interior, to the degree that objects are not clearly distinguishable when viewed through a specimen of the material
Term
LASER acronym
Definition
light amplification by stimulated emission of radiation
Term
photoconductivity
Definition
attendant increase in conductivity, photon-induced electron transitions in which light is absorbed
Term
light-emitting diode
Definition
the device that produces electroluminiscence
Supporting users have an ad free experience!