Cobalt is an example of a ______ material.
Paramagnetic
Diamagnetic
Ferromagnetic
Non- magnetic
Correct Answer :
C. Ferromagnetic
Related Questions
Which of the following electric quantities is vector in character?
Field
Charge
Energy
Potential Difference
What is the SI unit of magnetic flux?
Tesla
Weber
Maxwell
Gauss
The process by which an emf and hence current is generated or induced in a conductor when there is a change in the magnetic flux linking the conductor is called
Electromagnetic induction
Mutual induction
Faraday's law
Electromagnetic interference
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
The uncharged particles which have no effect on its atomic charge.
Nucleons
Electrons
Protons
Neutrons
What is the cgs unit of magnetomotive force?
Gilbert
Ampere- turn
Maxwell
Weber
Hysteresis loss can be reduced by one of the following.
Increasing mmf of the circuit
Using material narrow hysteresis loop
Using ferromagnetic core
Laminating the magnetic circuit
The temperature coefficient of resistance of conductors is
positive
zero
negative
infinite
What is the value of the absolute permittivity of air?
8.854 F/m
8.854 × 10^-12 mF/m
8.854× 10^-12 F/m
8.854 × 10^-12 F/m
The magnetic materials should have a large hysteresis loss for one of the following applications.
Transformers
ACmotors
Permanent Magnets
DC generators
If the magnetic material is located within a coil through which alternating current (60 Hz frequency) flowsa then __________ hysteresis loops will be formed
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 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 magnetic field around the conductor is determined by the
Size of the conductor
Amount of current
Current divided by the resistance
Resistance divided by the current
If the right handed bottle-opener cork screw is assumed to be along the conductor so as to advance in the direction of current flow, the motion of its handle will indicate the direction of magnetic flux produced around the conductor. This is known as
Right hand rule
Left hand rule
Cork screw rule
End rule
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
The electrons in the last orbit of an atom are called _______ electrons.
free
valence
bound
thermionic
What is the practical unit of electrical energy?
Watt
Kilowatt-hour
Kilowatt-second
Megawathour
What is the SI unit of reluctance?
At
At/m
N/Wb
At/Wb
The phenomenon by which a subtracts pieces of iron
Magnetism
Electromagnetism
Naturalism
Materialism
Why is it that the magnitude of magnetomotive force required for air gap is much greater than that required for iron part of a magnetic circuit?
Because air is a gas
Because air has the highest relative permeability
Because air is a conductor of magnetic flux
Because air has the lowest relative permeability
This paper does not exhibit electricity because it contains the same number of
protons and electrons
neutrons and electrons
neutrons and positrons
atoms
Amorphous solid is also called
Crystalline
Non- crystalline
Polycrystalline
Homogenous
All matters (gasa liquid and solid) are composed of
Neutrons
Particles
Electrons
Atoms
The emf induced in a coil due to the changing current of another neighboring coil is called
Mutually induced emf
Self induced emf
Statically induced emf
Dynamically induced emf
A 6- V battery is connected across a solenoid of 100 turns having a resistance of 2 ?a Calculate the number of ampere turns?
Lenz's law is the consequence of the law of conservation of
Energy
Charge
Field lines
Momentum
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 current of electric circuit is analogous to which quantity of a m
Mmf
Flux
Flux density
R eluctivity
There are how many compounds available in nature?
300a000
Unlimited