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
Correct Answer :
D. Lenz' law
Related Questions
What type of bond is formed when there exists some form of collective interactions between the (negatively charged) electrons and (positively charged) nuclei in a solid?
Ionic
Covalent
Metallic
Van der Waals
The mass of proton is __________ the mass of an electron.
equal to
about 1837 times
less than
200 tim es
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 contribution to the ionization in an ionization chamber by electrons liberated from t he walls.
Skin effect
Walt effect
Hall effect
Edison effect
Electromotive force in a circuit
causes free electrons to flow
increases the circuit resistance
maintains circuit resistance
is needed to make the circuit complete
When a wire loop is rotated in a magnetic field the direction of the induced emf changes one in every _______ revolution
Defined as a closed path in which magnetic induction or flux flows
Electric circuit
Magnetic circuit
Electronic circuit
Electromagnetic circuit
The point in a magnet where the intensity of magnetic lines of force is maximum
Magnetic pole
South pole
North pole
Unit pole
A good conductor has how many valence electrons?
A law that states that the current in a thermionic diode varies directly with the three- halves power of anode voltage and inversely with the square of the distance between the electrodesa provided operating conditions are such that the current is limited only by the space charge.
Hall's law
Joule's law
Child's law
Coulomb's law
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
Which of the following is a paramagnetic material?
Carbon
Copper
Bismuth
Oxygen
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
Hipernik is an alloy containing __________ iron and __________ nickel.
40% ; 60%
60% ; 40%
50% ; 50%
70% ; 30%
A t/m is a unit of
Mmf
Emf
Reluctance
Magnetizing force
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
A negative ion results when an atom gains an additional
Electron
Proton
Neutron
Atom
An alloy of 22 percent iron and 78 per cent nickel.
Permalloy
Alnico
Constantan
M anganin
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 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
The conduction of electricity across the surface of a dielectric is called
creepage
skin effect
surface effect
crosstalk
Magnetic field intensity is a ________ quantity.
scalar
phasor
vector
variable
The unit of flux density is
Wb/m
Tesla
At/m
N/Wb
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
The force of attraction or repulsion between two magnetic poles is directly proportional to their strengths.
Newton's first law
Faraday's first law of electromagnetic induction
Coulomb's first law
Coulomb's second law
There are how many compounds available in nature?
300a000
Unlimited
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
If the solenoid is gripped by the right hand with the fingers pointing the direction of current flowa the outstretched thumb will then point the north pole. This is known as
Right hand rule
Helix rule
End rule
Cork screw rule
The magnetic materials should have a large hysteresis loss for one of the following applications.
Transformers
ACmotors
Permanent Magnets
DC generators
Who demonstrated the theory of electromagnetic induction in 1831?
Michael Faraday
Andre Ampere
James Clerk Maxwell
Charles Coulomb