The force between two magnetic poles is _____ the relative permeability of the medium.
directly proportional to
independent of
inversely proportional to
equal to
Correct Answer :
C. inversely proportional to
Related Questions
A group of magnetically aligned atoms is called
Range
Lattice
Domain
Crystal
A permanent magnet does not exert a force on
an unmagnetized iron bar
a magnetized iron bar
a moving electric charge
a stationary electric charge
Residual magnetism refers to the flux densitya which exists in the iron core when the magnetic field intensity is
Minimized
Reduced to zero
Maximize
Unity
Whenever a flux inking a coil or current changesa an emf is induced in it. This is known as
Joule's Law
Coulomb's Law
Faraday's first law of electromagnetic induction
Faraday's second law of electromagnetic induction
What is the unit of reluctance?
Maxwell
Gauss
At/Wb
Weber
What determines the atomic number of an element?
The number of protons
The number of electrons
The number of neutrons
The number of neutrons and protons
What is the typical saturation flux density for most magnetic materials?
4 Wb/m^2
5 Wb/m^2
1 Wb/m^2
2 Wb/m^2
What is the practical unit of electrical energy?
Watt
Kilowatt-hour
Kilowatt-second
Megawathour
The permeability of permalloy is
Very much greater than permeability of air
Slightly greater than permeability of air
Slightly less than permeability of air
Equal to the permeability of air
Which of the following materials has the highest dielectric strength?
Glass
Oiled paper
Mica
Air
Who demonstrated the theory of electromagnetic induction in 1831?
Michael Faraday
Andre Ampere
James Clerk Maxwell
Charles Coulomb
An atom or a group of atoms that carries a net electric charge.
Positive ion
Negative ion
Ion
Electron
What revolves about the positive nucleus in a definite orbit?
Atom
Proton
Electron
Neutron
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 is a phenomenon of _________ in a magnetic circuit.
setting up constant flux
lagging of H behind B
lagging B behind H
leading B ahead H
Defined as the ratio of the volume occupied by the atoms or ions in a unit cell divided by the volume of the unit cell and is used to measure the compactness of a crystal.
Atomic packing factor (APF)
Ionic Packing Ratio (IPR)
Atomic compacting factor (ACF)
Ionic compacting ratio (ICR)
A magnetic flux of 2.5 x10^4 Wb through an area of 5 x10^4 square meters results in
5 Wb
0.5 Tesia of flux density
5x 10^-5 Wb of flux
5000 Tesia of flux density
Electric field intensity at a point due to a given charge ______ if the relative permittivity of the medium decreases.
decreases
remains unchanged
increases
b ecomes zero
All matters (gasa liquid and solid) are composed of
Neutrons
Particles
Electrons
Atoms
Who developed the electromagnetic theory of light in 1862?
Heinrich Rudolf Hertz
Wilhelm Rontgen
James Clerk Maxwell
Andre Ampere
The unit of flux is _____ in cgs system.
Tesia
Gilbert
Maxwell
Oersted
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
Who discovered superconductivity in 1911?
Kamerlingh Onnes
Alex Muller
GeoryBednorz
Charles Coulomb
A substance that attracts pieces iron
Conductor
Semiconductor
Magnet
All of the above
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
Core materials of a good relay have _________ hysteresis loop.
large
narrow
very large
very narrow
If the number of valence electrons of an atom is less than 4a then the substance is probably
a metal
an insulator
a non-metal
a semiconductor
Paramagnetic substance has a relative permeability of
Slightly less than one
Equal to one
Slightly equal to one
Very much greater than one
A negatively charge body has
deficit of electrons
excess of protons
excess of electrons
deficit of neutrons
Lenz's law is the consequence of the law of conservation of
Energy
Charge
Field lines
Momentum