One that has magnetic poles produced by internal atomic structure with no external current necessary
Diamagnetic
Permanent magnets
Paramagnetic
Electromagnetic
Correct Answer :
B. Permanent magnets
Related Questions
Cobalt is an example of a ______ material.
Paramagnetic
Diamagnetic
Ferromagnetic
Non- magnetic
The quantity 10^6 maxwells is equivalent to one
Weber
Gauss
Gilbert
Tesla
What type of bond is formed when there exists some form of collective interactions between the (negatively charged) electrons and (positively charged) nuclei in a solid?
Ionic
Covalent
Metallic
Van der Waals
The hot resistance of an incandescent lamp is about _______ its cold resistance.
10 times
100 times
5 times
50 times
What is the measure of the density and sign of the electric charge at a point relative to that at some time?
Electric potential
Electric charge
Electric current
Electric intensity
Permanent magnets can be found in
electric bells
earphones
relays
dy namic loudspeakers
What is the SI unit of conductivity?
Ohms/m
Ohms-m
Siemens-m
Siemens/m
The force between two magnetic poles is _____ the relative permeability of the medium.
directly proportional to
independent of
inversely proportional to
equal to
The ratio between the intensity of magnetization produced in a substance to the magnetizing force producing it
Magnetic Reluctivity
Magnetic Resistivity
Magnetic susceptibility
Magnetic conductivity
Flux linkages equals
Flux times area of core
Flux times number of turns times area of core
Flux times number of turns times length of core
Flux times number of turns
If the resistance of a material 2 m long and 2 m^2 in area of cross-section is 1.6 ×10^-8 ?a then its resistivity is
3.2 × 10^-8 ?-m
1.6 × 10^-8 ?-m
0.64 × 10^-8 ?-m
0.16 × 10^-8 ?-m
Hipernik is an alloy containing __________ iron and __________ nickel.
40% ; 60%
60% ; 40%
50% ; 50%
70% ; 30%
A 200-watt lamp working for 24 hours will consume approximately _____ units.
The lagging effect between flux density of the material and the magne
Permeance
Eddy current
Hysteresis
R eluctance
Materials that have very high permeabilities (hundreds and even thousands times of that of free space)
Paramagnetic
Non- magnetic
Ferromagnetic
Diamagnetic
How much is the flux in Weber in the above problem?
2 x 10^-5
2 x 10^-3
2 x 10^5
2 x 10^3
The magnetic field of a bar magnet most closely resembles the magnetic field of
a horseshoe magnet
a straight current- carrying wire
a stream of electrons moving parallel to one another
a current- carrying wire loop
Flux density is measured in
Tesia
Weber
Ampere- turn
Maxwell
The science of adapting electronics to aerospace flight.
Avionics
Aerotronics
Aerodynamics
Astrionics
What is the practical unit of electrical energy?
Watt
Kilowatt-hour
Kilowatt-second
Megawathour
What is the other name for dielectric strength?
Breakdown voltage
Electric intensity
Potential gradient
Dielectric constant
The idea of preventing one component from affecting another through their common electric and magnetic field is referred to as
Hall effect
Grounding
Shielding
Limiting
The temperature coefficient of resistance of eureka is
p ositive
negative
almost zero
i nfinite
Hysteresis refers to the ______ between flux density of the material and the magnetizing force applied.
Leading effect
Ratio
Equality
Lagging effect
Magnetic effects of the earth as a huge magnet with north and south poles.
Diamagnetic
Ferromagnetic
Terrestrial magnetism
Terrestrial ferromagnetism
All magnetic field originates from
moving electric charge
Iron atoms
Magnetic domain
Permanent magnets
What is the main advantage of temporary magnets?
The magnetic flux can be changed.
Hysteresis can be decreased.
Magnetic materials can be used.
Abundance of ferromagnetic material that can be temporarily magnetized.
The phenomenon that when an electric current passes through an anisotropic crystala there is an absorption or liberation of heat due to the non-uniformity in current distribution.
Bridgman effect
Corona effect
Dember effect
Destriau effect
In electro-mechanical conversion devices like generators and motors the reason why a small air gap is left between the rotor and stator is to
permit mechanical clearance
increase flux density in air gap
decrease the reluctance of magnetic path
complete the magnetic path
When the current flowsa the magnetic field ��. conductor is in what direction?
The same as the current direction
Opposite the current direction
Omnidirectional
In the direction determined by the left hand rule