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
Correct Answer :
B. Helix rule
Related Questions
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 magnetic flux through a wire loop in a magnetic field does not d
T he area of the loop
The magnitude of the field
The shape of the loop
The angle between the plane of the loop and the direction
A principle that states that only two electrons with different spins are allowed to exist in a given orbit
Bohr's principle
Pauli exclusion principle
Avogadro's principle
Coulomb's principle
Referred to as the specific reluctance of a material
Resistivity
Reluctivity
Conductivity
Permeability
Bonding of atoms that is due to the force of attraction between positive ions and a group of negative ions
Ionic bond
Covalent Bond
Electrostatic Bond
Metallic bond
Which of the following materials has the least hysteresis loop area?
soft iron
silicon steel
hard steel
wrought iron
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
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
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
Under ordinary conditionsa a body is considered
positively charged
neutral
negatively charged
stable
How many electrons are needed in the valence orbit to give a material's stability?
Who demonstrated the theory of electromagnetic induction in 1831?
Michael Faraday
Andre Ampere
James Clerk Maxwell
Charles Coulomb
Back emf refers to the
Current equal to the applied emf
Opposing emf
Current opposing the applied emf
Voltage opposing the applied emf
The emission of electrons from hot bodies is called
Radiation effect
Edison effect
Skin effect
Half effect
When the relative permeability of a material is much greater than 1a it is called _______ material.
diamagnetic
ferromagnetic
paramagnetic
non-magnetic
The customary energy unit in atomic and nuclear physics is
Joule
Volt- coulomb
electron-volt
Walt- second
The energy stored in an electrostatic field or electromagnetic field is called
Electromagnetic energy
Kinetic energy
Potential energy
R est energy
Magnetic fields do not interact with
Moving permanent magnets
Stationary permanent magnets
Moving electric charges
Stationary electric charges
An effect which is generally used in the gausameter to measure flux density.
Skin effect
Magnetic effect
Hall effect
Flywheel effect
The resistivity of a conductor ___________ with an increase in temperature.
increases
decreases
remains the same
becomes zero
The mass of proton is __________ the mass of an electron.
equal to
about 1837 times
less than
200 tim es
Electronic current in a wire is the flow of ____________ electrons.
free
valence
bound
loose
The hot resistance of an incandescent lamp is about _______ its cold resistance.
10 times
100 times
5 times
50 times
Which of the following is a paramagnetic material?
Carbon
Bismuth
Copper
Oxygen
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 physical motion resulting from the forces of magnetic fields is called
Motor action
Rotation
Repulsion
Torque action
It is the reciprocal of reluctance and implies the case of readiness with which magnetic flux is developed.
R esistance
Conductance
Permeance
I nductance
The evaporation of electrons from a heated surface is called
Radiation
Convection
Thermionic emission
Conduction
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