The core of a magnetic equipment uses a magnetic material with
Least permeability
Low permeability
Moderate permeability
High permeability
Correct Answer :
D. High permeability
Related Questions
Magnetic field intensity is a ________ quantity.
scalar
phasor
vector
variable
Amorphous solid is also called
Crystalline
Non- crystalline
Polycrystalline
Homogenous
One oersted (Oe) is equivalent to _____ Gb/cm.
Formed when there exist distant electronic interactions between (opposite) charges present in the neighboring atoms or molecules.
Ionic bond
Covalent bond
Metallic bond
Van der Waals bond
The tiniest element of matter
Atom
Proton
Electron
Neutron
A t/m is a unit of
Mmf
Emf
Reluctance
Magnetizing force
Electric field intensity at a point is numerically equal to ________ at that point.
potential gradient
potential difference
dielectric constant
the force
Ohm's law cannot be applied to which material?
Copper
Silver
Silicon carbide
Aluminum
The lagging effect between flux density of the material and the magne
Permeance
Eddy current
Hysteresis
R eluctance
The relative permeability of a magnetic material is 10^5. What is its permeability?
4 × 10^5 H/m
4 × 10^-12 H/m
4× 10^-2 H/m
4 × 10^7H/m
Permanent magnets can be found in
electric bells
earphones
relays
dy namic loudspeakers
The magnetic flux through a coil changes. This results to the induced emf acting in a direction as to
Oppose the change
Aid the change
Either oppose or aid the change
Neither oppose nor aid the change
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
If the value of 0 a conductor is 1/234 per oCa then the value of 18is
1/218 per oC
1/252 peroC
1/272 per oC
1/273 per oC
If the number of valence electrons of an atom is exactly 4a then the substance is called
a semiconductor
a conductor
an insulator
a cryogenic conductor
Electric field intensity is a ________.
scalar
phasor
vector
variable
The air space between poles of magnets
Air gap
Free space
Vacuum
Atmosphere
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
Calculate the flux density that will be produced by the field intensity of 2000 a. t/m for a permeability of 126 x 10^-6 T/A.t/m
0.252 G
0.252 x 10^-2 T
0.252 T
0.252 x 10^-2 G
The unit of electrical energy is
Joule
Watt- second
Kilowatt hour
All of these
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
Which of the following has the least number of valence electrons?
Conductor
Semiconductor
Insulator
Semi- insulator
A positively charged body has
deficit of electrons
excess of neutrons
excess of electrons
deficit of protons
What is the main advantage of temporary magnets?
The magnetic flux can be changed.
Hysteresis can be decreased.
Magnetic materials can be used.
Abundance of ferromagnetic material that can be temporarily magnetized.
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 is a natural magnet?
Steel
Magnesia
Lodestone
S oft iron
If two similar charges 1 coulomb each are placed 1 m apart in aira then the force of repulsion is
8 × 10^6 N
9 × 10 ^9 N
10^6 N
5 × 10^6 N
______ is an electromagnet with its core in the form of a close magnetic ring.
S olenoid
Paraboloid
Toroid
Cycloid
A length of wire has a resistance of 10 ohms. What is the resistance of a wire of the same material three times as long and twice the cross-sectional area?
30 ohms
20 ohms
15 ohms
7 ohms
A factor used to correct for the electrostatic forces of the more distant ions in an ionic solid.
Avogadro's number
Planck's constant
Boltzmann's constant
Madelung constant