Small voltages generated by a conductor with current in an external magnetic field.
Skin effect
Magnetic effect
Hall effect
Flywheel Effect
Correct Answer :
C. Hall effect
Related Questions
Which of the following electric quantities is vector in character?
Field
Charge
Energy
Potential Difference
Which of the following magnetic materials can be easily magnetized in both direction?
Soft magnetic materials
Hard magnetic materials
High hysteresis loss materials
Low hysteresis loss materials
Referred to as the specific reluctance of a material
Resistivity
Reluctivity
Conductivity
Permeability
Used to maintain strength of magnetic field
Container
Air gap
Keeper
S ource
Steel is hard to magnetize because of its
Low permeability
High permeability
High density
High retentivity
A law establishing the fact that the algebraic su of the rises and drops of the mmf around a closed loop of a magnetic circuit is equal to zero.
Kirchhoff's circuital law
Maxwell's circuital law
Ampere's circuital law
Coulomb's circuital law
Electric lines of force leave or enter the charge surface at an angle of
30o
45 o
90o
depending upon the angle of launch and entry
Who demonstrated the theory of electromagnetic induction in 1831?
Michael Faraday
Andre Ampere
James Clerk Maxwell
Charles Coulomb
The force acting on a pole of 5 Wb is 25 N. What is the intensity of the magnetic field?
5 N/Wb
25 N/Wb
125 N/Wb
0.2 N/Wb
Which of the following materials has the least hysteresis loop area?
soft iron
silicon steel
hard steel
wrought iron
The hot resistance of an incandescent lamp is about _______ its cold resistance.
10 times
100 times
5 times
50 times
The electric flux density is a ________ quantity.
phasor
vector
scalar
variable
Small voltages generated by a conductor with current in an external magnetic field.
Skin effect
Magnetic effect
Hall effect
Flywheel Effect
The unit of flux density is
Wb/m
Tesla
At/m
N/Wb
Refers to the magnetic lines
Flux
Hysteresis
Current
Magnetomotive force
How many electrons are needed in the valence orbit to give a material's stability?
A substance that attracts pieces iron
Conductor
Semiconductor
Magnet
All of the above
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
Materials that have very high permeabilities (hundreds and even thousands times of that of free space)
Paramagnetic
Non- magnetic
Ferromagnetic
Diamagnetic
At/m is a unit of
mmf
magnetic force
reluctance
magnetic flux density
A law stating that the magnetic susceptibilities of most paramagnetic substances are inversely proportional to their absolute temperatures.
Curie's Law
Child's Law
CR Law
Curie-Weiss Law
If the number of valence electrons of an atom is more than 4a the substance is called
a semiconductor
a conductor
an insulator
a semi-insulator
The temperature coefficient of resistance of semiconductors is
positive
zero
negative
infinite
Ohm's law cannot be applied to which material?
Copper
Silver
Silicon carbide
Aluminum
Permeability means
The conductivity of the material for magnetic lines of force
The magnetization test in the material after exciting field has been removed
The strength of an electromagnet
The strength of the permanent magnet
Which element has four valence electrons?
Conductor
Insulator
Semiconductor
Semi- insulator
One of the solid structures in which the position of the atoms or ions are predetermined
Crystalline solid
Amorphous solid
Polycrystalline solid
Poly amorphous solid
Electric potential is a _______ quantity.
scalar
phasor
vector
variable
The electric potential at a point in air due to a charge is 21 V. If the air is replaced by a medium of relative permittivity of 3a then electric potential at that point will be
63 V
21 V
7 V
42 V
Lenz' law states that the direction of the induced emf and hence current
Is determined by the rate of current flux
Is found by the right hand rule
Is found by the left hand rule
Always opposes the cause producing it