All magnetic field originates from
moving electric charge
Iron atoms
Magnetic domain
Permanent magnets
Correct Answer :
A. moving electric charge
Related Questions
Magnetic intensity is a
Phasor quantity
Physical quantity
Scalar quantity
Vector quantity
How many electrons are needed in the valence orbit to give a material's stability?
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
What is used as the insulating material or dielectric in an electric ion
Oiled paper
Mica
Paraffin
Tit anate compound
The tiniest element of matter
Atom
Proton
Electron
Neutron
The reluctance of a magnetic circuit varies with
length × area
area � length
length � area
length + area
The force between two magnetic poles varies with the distance between them. The variation is ______ to the square of that distance.
Equal
Greater than
Directly proportional
Inversely proportional
The dielectric constant of most materials lies between
1 and 10
10 and 20
20 and 50
50 and 100
When a conductor is stationary and the magnetic field is moving or changing the emf induced is called
Statically induced emf
Mutually induced emf
Self induced emf
Dynamically induced emf
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
Magnetic field intensity is a ________ quantity.
scalar
phasor
vector
variable
Referred to as the specific reluctance of a material
Resistivity
Reluctivity
Conductivity
Permeability
What is another name for relative permittivity?
Dielectric strength
Electric intensity
Potential gradient
Dielectric constant
Electrons at the outer shell are called
Outer shell electrons
Inner shell electrons
Semiconductor electrons
Valence electrons
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
A magnetic field is
The current flow through space around a permanent magnet
The force set up when current flows through a conductor
The force that drives current through a resistor
The force between the plates of a charged capacitor
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
The amount of magnetizing force to counter balance the resid magnetic material is referred to as
Reluctivity
Susceptivity
Coercivity
Retentivity
What is the practical unit of electrical energy?
Watt
Kilowatt-hour
Kilowatt-second
Megawathour
Hysteresis refers to the ______ between flux density of the material and the magnetizing force applied.
Leading effect
Ratio
Equality
Lagging effect
The permeability of a material having a flux density of 5 Wb/m^2 is 10^-5 H/m. What is the value of magnetizing force?
5 × 10^-5 N/Wb
500 × 10^3 N/Wb
4 × 10^7N/Wb
4 × 10^7N/Wb
Which of the following electric quantities is vector in character?
Field
Charge
Energy
Potential Difference
The physical motion resulting from the forces of magnetic fields is called
Motor action
Rotation
Repulsion
Torque action
The magnetic potential in a magnetic circuit can be measured in terms of
Mmf
Emf
Farad
Coulomb
Which of the following materials has permeability slightly less than that of free space?
Paramagnetic
Non- magnetic
Ferromagnetic
Diamagnetic
The direction of force o a current carrying conductor placed in a m found by
Cork screw rule
Fleming's left hand rule
Fleming's right hand rule
using a compass
What is the SI unit of conductance?
Siemens
Mhos
Ohms
1/Ohms
An electron- volt (eV) is a unit of
Energy
Potential difference
Charge
Momentum
One oersted (Oe) is equivalent to _____ Gb/cm.
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