The quantity of magnetism retained by a magnetic material after withdrawal of the magnetizing force is called
Leftover magnetism
Hysteresis
Residual magnetism
Coercivity
Correct Answer :
C. Residual magnetism
Related Questions
Calculate the permeability (in T/A. t/m) of a magnetic material that has a relative permeability of 300
3.78 x 10^4
3.78 x 10^-5
3.78 x 10^-3
3.78 x 10^-6
Which of the following materials has permeability slightly less than that of free space?
Paramagnetic
Non- magnetic
Ferromagnetic
Diamagnetic
The contribution to the ionization in an ionization chamber by electrons liberated from t he walls.
Skin effect
Walt effect
Hall effect
Edison effect
Materials whose permeabilities are slightly greater than that of free space
Paramagnetic
Non- magnetic
Ferromagnetic
Diamagnetic
Which of the following magnetic materials can be easily magnetized in both direction?
Soft magnetic materials
Hard magnetic materials
High hysteresis loss materials
Low hysteresis loss materials
What is the SI unit of conductivity?
Ohms/m
Ohms-m
Siemens-m
Siemens/m
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
The phenomenon by which a magnetic substance becomes a magnet when it is place near a magnet
Magnetic effect
Magnetic phenomenon
Magnetic induction
Electromagnetic induction
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
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 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
Materials that have very high permeabilities (hundreds and even thousands times of that of free space)
Paramagnetic
Non- magnetic
Ferromagnetic
Diamagnetic
The quantity 10^6 maxwells is equivalent to one
Weber
Gauss
Gilbert
Tesla
The customary energy unit in atomic and nuclear physics is
Joule
Volt- coulomb
electron-volt
Walt- second
The electric flux density is a ________ quantity.
phasor
vector
scalar
variable
A group of magnetically aligned atoms is called
Range
Lattice
Domain
Crystal
Who developed the electromagnetic theory of light in 1862?
Heinrich Rudolf Hertz
Wilhelm Rontgen
James Clerk Maxwell
Andre Ampere
An alloy of 22 percent iron and 78 per cent nickel.
Permalloy
Alnico
Constantan
M anganin
What is the usual value of leakage coefficient for electrical machines?
0.5 to 1
1 to 5
5 to 10
1.15 to 1.25
The evaporation of electrons from a heated surface is called
Radiation
Convection
Thermionic emission
Conduction
Magnetic intensity is a
Phasor quantity
Physical quantity
Scalar quantity
Vector quantity
Permeance is analogous to
Conductance
Reluctance
Admittance
Resistance
One of the common application of an air- cored choke.
Radio frequency
Audio frequency
Power supply
Power transformer
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 temperature coefficient of resistance of eureka is
p ositive
negative
almost zero
i nfinite
This paper does not exhibit electricity because it contains the same number of
protons and electrons
neutrons and electrons
neutrons and positrons
atoms
The force acting on a unit n- pole placed at that point is called
Magnetic field intensity
Electric field intensity
Electromagnetic field intensity
Intensity magnetization
Which of the following is a vector quantity?
Magnetic potential
Magnetic field intensity
Magnetic permeability
F lux density
The magnetic flux of 2000 lines is how many Maxwells?
The phenomenon by which a subtracts pieces of iron
Magnetism
Electromagnetism
Naturalism
Materialism