An effect which is generally used in the gausameter to measure flux density.
Skin effect
Magnetic effect
Hall effect
Flywheel effect
Correct Answer :
C. Hall effect
Related Questions
Permanent magnets can be found in
electric bells
earphones
relays
dy namic loudspeakers
Which of the following statements is TRUE?
Silicon dioxide is a good
The current carriers in conductors are valence electrons
For conductorsa the valence electron are strongly attracted to the nucleus
The valence electrons are located in the nucleus of an atom
The magnetic energy stored in an inductor is ______ current.
Directly proportional to
Inversely proportional to
Directly proportional to the square of
Inversely proportional to the square of
Hysteresis loss can be reduced by one of the following.
Increasing mmf of the circuit
Using material narrow hysteresis loop
Using ferromagnetic core
Laminating the magnetic circuit
How is mutual inductance between two coils decreased?
By using a common core
By moving the coils closer
By moving the coils apart
By increasing the number of turns of either coil
The electrons in the last orbit of an atom are called _______ electrons.
free
valence
bound
thermionic
Germanium atom has ______ protons and ______ electrons.
32, 32
32, 42
42, 32
34, 34
The force of attraction or repulsion between two magnetic poles is directly proportional to their strengths.
Newton's first law
Faraday's first law of electromagnetic induction
Coulomb's first law
Coulomb's second law
The tiniest element of matter
Atom
Proton
Electron
Neutron
Which element has four valence electrons?
Conductor
Insulator
Semiconductor
Semi- insulator
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
Which of the following has the least number of valence electrons?
Conductor
Semiconductor
Insulator
Semi- insulator
When the relative permeability of a material is slightly less than 1a it is called _____ material.
diamagnetic
ferromagnetic
paramagnetic
non-magnetic
The electric flux density is a ________ quantity.
phasor
vector
scalar
variable
The physical motion resulting from the forces of magnetic fields is called
Motor action
Rotation
Repulsion
Torque action
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
The magnetic field inside a solenoid
is zero
is uniform
increases with distance from the axis
decreases with distance from the axis
The current of electric circuit is analogous to which quantity of a m
Mmf
Flux
Flux density
R eluctivity
What is the reluctance of a magnetic path having a length of 2x 10^-3m and crosssectional area of 2.5 x 10^-3 m^2?
6366 A, t/Wb
6000 A, t/Wb
8x10^-3 A, t/Wb
0.8 A, t/Wb
If on looking at any one end of a solenoid; the direction of current flow is found to be clockwise then the end under observation is a south pole. This is known as
Right hand rule
Left hand rule
Cork screw rule
End Rule
A magnetizing force of 1000 AT/m will produce a flux density of __________ i
1.257 mWb/m^2
0.63 Wb/m^2
1.257 Wb/m^2
0.63 mWb/m^2
A one cubic cm of copper has how many free electrons at room temperature?
80 × 10^18
8.5 × 10^22
20 × 10^10
50 × 10^20
The B-H curve of ________ is not a straight line.
air
wood
silicon steel
soft iron
The unit of electrical energy is
Joule
Watt- second
Kilowatt hour
All of these
One weber of flux is equal to _______ magnetic lines of force.
10^6
10^10
4 × 10^7
10^8
Which of the following is used by temporary magnets as the magnetic material?
Hardened steel
Cobalt steel
Soft iron
Tungsten steel
Amorphous solid is also called
Crystalline
Non- crystalline
Polycrystalline
Homogenous
The force of attraction or repulsion between two magnetic poles is inversely proportional to the square of the distance between them. This is known as
Newton's first law
Faraday's first law of electromagnetic induction
Coulomb's first law
Coulomb's second law
Lenz's law is the consequence of the law of conservation of
Energy
Charge
Field lines
Momentum
What solid has no defined crystal structure except perhaps in the arrangement of the nearest neighboring atoms or ions?
Crystalline
Amorphous
Polycrystalline
Poly amorphous