How is mutual inductance between two coils decreased?
By using a common core
By moving the coils closer
By moving the coils apart
By increasing the number of turns of either coil
Correct Answer :
C. By moving the coils apart
Related Questions
An electron- volt (eV) is a unit of
Energy
Potential difference
Charge
Momentum
An alloy of 22 percent iron and 78 per cent nickel.
Permalloy
Alnico
Constantan
M anganin
An atom or a group of atoms that carries a net electric charge.
Positive ion
Negative ion
Ion
Electron
How many neutrons does a copper atom have?
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
One that has magnetic poles produced by internal atomic structure with no external current necessary
Diamagnetic
Permanent magnets
Paramagnetic
Electromagnetic
The property of magnetic materials of retaining magnetism after withdrawal of the magnetizing force is known as
Retentivity
Reluctivity
Resistivity
Conductivity
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
Which of the following is a vector quantity?
Magnetic potential
Magnetic field intensity
Magnetic permeability
F lux density
The electric flux density is a ________ quantity.
phasor
vector
scalar
variable
The property of a material which opposes the creation of magnetic flux in it
Resistance
Reluctance
Permeance
Conductance
If on looking at any one end of a solenoid; the direction of current flow is found to be clockwise then the end under observation is a south pole. This is known as
Right hand rule
Left hand rule
Cork screw rule
End Rule
A group of magnetically aligned atoms is called
Range
Lattice
Domain
Crystal
The evaporation of electrons from a heated surface is called
Radiation
Convection
Thermionic emission
Conduction
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 force between two magnetic poles is _______ their pole strengths.
directly proportional to
the sum of
inversely proportional to
the product of
The uncharged particles which have no effect on its atomic charge.
Nucleons
Electrons
Protons
Neutrons
Temporary magnets are commonly employed in
electric instruments
motors
moving coils loudspeakers
magnetos
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 negatively charge body has
deficit of electrons
excess of protons
excess of electrons
deficit of neutrons
One coulomb of charge consists of ________ electrons.
624× 10^16
62.4 × 10^16
6.24 × 10^16
0.624 × 10^16
Which of the following has the least number of valence electrons?
Conductor
Semiconductor
Insulator
Semi- insulator
Permanent magnets can be found in
electric bells
earphones
relays
dy namic loudspeakers
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
The core of a magnetic equipment uses a magnetic material with
Least permeability
Low permeability
Moderate permeability
High permeability
A t/m is a unit of
Mmf
Emf
Reluctance
Magnetizing force
Hydrogen is an example of a _____ material.
Paramagnetic
Diamagnetic
Ferromagnetic
N on- magnetic
Core materials of a good relay have _________ hysteresis loop.
large
narrow
very large
very narrow
Who discovereda the relationship between magnetism and electricity that serves as the foundation for the theory of electromagnetism?
Luigi Galvani
Hans Christian Oersted
Andre Ampere
Charles Coulomb
Electronic current in a wire is the flow of ____________ electrons.
free
valence
bound
loose