What is the diameter of an atom?
About 10^-10 m
About 10^-10 cm
About 10^-10 mm
About 10^-10 �m
Correct Answer :
A. About 10^-10 m
Related Questions
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
Which of the following is used by temporary magnets as the magnetic material?
Hardened steel
Cobalt steel
Soft iron
Tungsten steel
The evaporation of electrons from a heated surface is called
Radiation
Convection
Thermionic emission
Conduction
______ is an electromagnet with its core in the form of a close magnetic ring.
S olenoid
Paraboloid
Toroid
Cycloid
Cobalt is an example of a ______ material.
Paramagnetic
Diamagnetic
Ferromagnetic
Non- magnetic
Electron is a Greek word for
amber
Fire
Stone
Heat
Hydrogen is an example of a _____ material.
Paramagnetic
Diamagnetic
Ferromagnetic
N on- magnetic
All matters (gasa liquid and solid) are composed of
Neutrons
Particles
Electrons
Atoms
Hysteresis refers to the ______ between flux density of the material and the magnetizing force applied.
Leading effect
Ratio
Equality
Lagging effect
What is the SI unit of specific resistance or resistivity?
Ohm-circular mil per inch
Ohm-circular mil per foot
Ohm-m
Ohm-cm
The force which set ups or tends to set up magnetic flux in a magnetic circuit
Dynamic force
Electromotive force
Potential difference
Magnetomotive force
Gases whose particles are charged are known as
Conductors
Insulators
Gaseous Conductors
Plasma
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
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
Which of the following is used by permanent magnets as the magnetic material?
iron
nickel
soft steel
hardened steel
A permanent magnet does not exert a force on
an unmagnetized iron bar
a magnetized iron bar
a moving electric charge
a stationary electric charge
What is the unit of magnetomotive force?
Volt
Tesla
Ampere- turn
Weber
The science of adapting electronics to aerospace flight.
Avionics
Aerotronics
Aerodynamics
Astrionics
Which of the following is a vector quantity?
Magnetic potential
Magnetic field intensity
Magnetic permeability
F lux density
What is the SI unit of magnetic flux?
Tesla
Weber
Maxwell
Gauss
What is the cgs unit of magnetomotive force?
Gilbert
Ampere- turn
Maxwell
Weber
The permittivity of a material is given by one of the following formulas.
DE
E/D
D^2/E
D/E
Materials whose permeabilities are slightly greater than that of free space
Paramagnetic
Non- magnetic
Ferromagnetic
Diamagnetic
Formed when there exist distant electronic interactions between (opposite) charges present in the neighboring atoms or molecules.
Ionic bond
Covalent bond
Metallic bond
Van der Waals bond
When the current flowsa the magnetic field ��. conductor is in what direction?
The same as the current direction
Opposite the current direction
Omnidirectional
In the direction determined by the left hand rule
The phenomenon by which a subtracts pieces of iron
Magnetism
Electromagnetism
Naturalism
Materialism
One of the solid structures in which the position of the atoms or ions are predetermined
Crystalline solid
Amorphous solid
Polycrystalline solid
Poly amorphous solid
Permeance of a magnetic circuit is _________ the cross-sectional area of the circuit.
directly proportional to
inversely proportional to
dependent of
independent of
A law stating that the magnetic susceptibilities of most paramagnetic substances are inversely proportional to their absolute temperatures.
Curie's Law
Child's Law
CR Law
Curie-Weiss Law
Theory of ferromagnetic phenomena which assumes each atom is a permanent magnet which can turn freely about its center under the influence of applied field and other magnets.
Ewing's theory of ferromagnetism
Oersted's ferromagnetism theory
Maxwell's magnetic theory
Ampere's circuital law