When the relative permeability of a material is slightly less than 1a it is called _____ material.
diamagnetic
ferromagnetic
paramagnetic
non-magnetic
Correct Answer :
A. diamagnetic
Related Questions
The physical motion resulting from the forces of magnetic fields is called
Motor action
Rotation
Repulsion
Torque action
______ is an electromagnet with its core in the form of a close magnetic ring.
S olenoid
Paraboloid
Toroid
Cycloid
What is the diameter of an atom?
About 10^-10 m
About 10^-10 cm
About 10^-10 mm
About 10^-10 �m
The net electrical charge in an isolated system remains constant. This is known as
Law of conservation of charge
Coulomb's first law
Coulomb's second law
Law of conservation of energy
The potential at a point due to a charge is 15 V. If the distance is times, the potential at the point will be
5 V
18 V
45 V
15 V
If a magnetic flux cuts across 200 turns at a rate of 2Wb/sa the induced voltage according to Faraday's law is about
400 V
100 V
200 V
600 V
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
Whenever a conductor cuts magnetic fluxa an emf is induced in it. This is known as
Coulomb's law
Joule's law
Faraday's law
Ohm's law
What is the practical unit of electrical energy?
Watt
Kilowatt-hour
Kilowatt-second
Megawathour
The space outside the magnet where its pole have a force of attraction or repulsion on a magnetic pole is called
Magnetic field
Electric field
Electromagnetic field
Free Space Field
What is used as the insulating material or dielectric in an electric ion
Oiled paper
Mica
Paraffin
Tit anate compound
A law that states that the polarity of the induced voltage will oppose the change in magnetic flux causing the induction.
Joule's law
Faraday's law
Coulomb's law
Lenz' law
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
How many turns are needed to produce a magnetomotive force of 1000 A.t for a coil with 6 amperes?
6000 turns
600 turns
167 turns
67turns
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
Materials that have very high permeabilities (hundreds and even thousands times of that of free space)
Paramagnetic
Non- magnetic
Ferromagnetic
Diamagnetic
Which of the following is a natural magnet?
Steel
Magnesia
Lodestone
S oft iron
The temperature coefficient of resistance of eureka is
p ositive
negative
almost zero
i nfinite
The unit of flux is _____ in cgs system.
Tesia
Gilbert
Maxwell
Oersted
Refers to the non- metallic materials that have the ferromagnetic properties of iron.
Ferrites
Ferromagnetic
Diamagnetic
Paramagnetic
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
Permanent magnets can be found in
electric bells
earphones
relays
dy namic loudspeakers
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
The electrons in the last orbit of an atom are called _______ electrons.
free
valence
bound
thermionic
The reluctance of a magnetic circuit is not dependent on which of the following?
Number of turns of coil
Magnetomotive force
Flux density in the circuit
Current in the coil
Which of the following materials has the highest dielectric strength?
Glass
Oiled paper
Mica
Air
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
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 potential in a magnetic circuit can be measured in terms of
Mmf
Emf
Farad
Coulomb
The magnitude of the induced emf in a coil is directly proportional to the rate of change of flux linkages. This is known as
Joule's Law
Faraday's second law of electromagnetic induction
Faraday's first law of electromagnetic induction
Coulomb's Law