Who demonstrated that there are magnetic effects around every current-carrying conductor and that current-carrying conductors can attract and repel each other just like magnets?
Luigi Galvani
Hans Christian Oersted
Charles Coulomb
Andre Ampere
Correct Answer :
D. Andre Ampere
Related Questions
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 force between two magnetic poles is _____ the relative permeability of the medium.
directly proportional to
independent of
inversely proportional to
equal to
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 branch of Engineering which deals with the magnetic effect of electric current is known as
Magnetism
Electromagnetism
Electrical engineering
Electronics engineering
Permeability means
The conductivity of the material for magnetic lines of force
The magnetization test in the material after exciting field has been removed
The strength of an electromagnet
The strength of the permanent magnet
The greater percentage of materials is _________.
diamagnetic
paramagnetic
ferromagnetic
non-magnetic
A factor used to correct for the electrostatic forces of the more distant ions in an ionic solid.
Avogadro's number
Planck's constant
Boltzmann's constant
Madelung constant
A negatively charge body has
deficit of electrons
excess of protons
excess of electrons
deficit of neutrons
Define as that pole which when placed in air from a similar and equal pole repels it with a force of newtons
North pole
South pole
Unit pole
Magnetic pole
A law relating between the magnetic and electric susceptibilities and the absolute temperatures which is followed b ferromagnetsa antiferromagnetsa non-polar ferroelectricsa antiferroelectrics and some paramagnets.
Curie's Law
Child's Law
CR Law
Curie-Weiss Law
When the relative permeability of a material is slightly less than 1a it is called _____ material.
diamagnetic
ferromagnetic
paramagnetic
non-magnetic
One farad equals
1 coulomb/volt
1 newton/coulomb
1 newton-meter
1 volt/second/ampere
__________ is a substance of whose molecules consist of the same kind of atom.
Mixture
Compound
Element
Isotope
Which element has four valence electrons?
Conductor
Insulator
Semiconductor
Semi- insulator
The hot resistance of an incandescent lamp is about _______ its cold resistance.
10 times
100 times
5 times
50 times
As the magnetic intensity decreasesa the relative permeability of a magnetic material
decreases
remains the same
increases
becomes zero
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
One weber of flux is equal to _______ magnetic lines of force.
10^6
10^10
4 × 10^7
10^8
What is the maximum number of electrons that can be accommodated in the last orbit of an atom?
If the distance between two magnetic poles decreases by 2 timesa the force between them
decreases two times
increases four times
increases two times
decreases four times
The physical motion resulting from the forces of magnetic fields is called
Motor action
Rotation
Repulsion
Torque action
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
The lagging effect between flux density of the material and the magne
Permeance
Eddy current
Hysteresis
R eluctance
The magnetic field of a bar magnet most closely resembles the magnetic field of
a horseshoe magnet
a straight current- carrying wire
a stream of electrons moving parallel to one another
a current- carrying wire loop
The magnetic field of a magnetized iron bar when strongly heated
Becomes weaker
Becomes stronger
Reverses in direction
is unchanged
Which of the following has the highest permeability?
Soft iron
Steel
Air
Permalloy
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
Who discovered superconductivity in 1911?
Kamerlingh Onnes
Alex Muller
GeoryBednorz
Charles Coulomb
Who discovered the most important electrical effects which is the magnetic effect?
Hans Christian Oersted
Sir Charles Wheatstone
Georg Ohm
James Clerk Maxwell
If the number of valence electrons of an atom is exactly 4a then the substance is called
a semiconductor
a conductor
an insulator
a cryogenic conductor