Macroscopic
Large
enough to be perceived or examined by naked eye.
(or)
Anything
which is considered for bulk of matter as a whole.
Magnetic
Dipole
An object such as current loop, an atom or a bar magnet,
that experiences torques due to magnetic forces.
Magnetic
Field Intensity
It is measured by
force acting on unit magnetic pole. The field intensity is also specified by number
of lines of force intersecting unit area normal to the field, equal numerically
to field strength in Oersted.
Magnetic
Induction
When any
substance is subjected to a magnetic field, the magnetic flux per unit area
taken perpendicular to direction of the flux is called magnetic induction.
Magnetic
Permeability
Property of
materials modifying the action of magnetic poles placed there in and modifying
the magnetic induction resulting when the material is subjected to a magnetic
field or magnetizing force. The permeability may be defined as ratio of
magnetic induction in the substance to magnetizing field to which it is
subjected.
Magic
Number
When
the number of protons is 2,8,20,28,50,82 or the no. of neutrons is
2,8,20,28,50,82,126 the nucleus is observed particularly stable and these
numbers are referred to as magic numbers. Nuclei in which the no. of protons as
well as no. of neutrons is equal to magic number belong to most stable group of
nuclei.
Magnetic
Dipole
Small bar magnet
composed of north and south poles.
Magnetic
Flux Density
Also called as magnetic induction
represents magnitude of internal field strength with in a substance that is
subjected to an external magnetic field.
Magnetic
Moment
A vector quantity that is a measure of the torque exerted on
a magnetic system when placed in magnetic field and that for a magnet is the
product of distance between its poles and the strength of either pole. It is
usually created by electric current flowing in wire or with orbital motion of spinning
electron caused intrinsic magnetic moment.
Magnetic
Potential
Magnetic potential at a point is measured by the work
required to bring unit positive pole from an infinite distance (zero potential)
to the point.
Magnetic
Resonance Imaging (MRI)
The use of magnetic fields and radio waves
(instead of the X-rays employed in the CT scan) to visualize body structures
and how they function. The powerful magnet, large enough to enclose the body,
forces the atomic nuclei in most material such as soft tissue to align themselves
with the magnetic field. Radio waves are aimed at the selected area to excite
the atoms which, when the waves are stopped, emit signals that are converted to
computer-generated pictures.
Magnetic
Susceptibility
It is a dimension less quantity and is
proportionality constant between magnetization & applied external magnetic
field.
Magnetism
Old study which deals with simplest sources of magnetic
fields, the permanent (bar) magnets. Magnets and magnetic fields are dealt
without considering electrical charges in motion.
Magnetization
The
phenomenon of formation of magnetic dipoles inside material due to application
of uniform magnetic field.
(or)
The
total magnetic moment per unit volume of material is called as
magnetization.
Magnetoresistance
It is property of
crystal to change its electrical resistance when a magnetic field is imposed on
it.
Magnetometer
An instrument
used for measuring the intensity or direction of a magnetic field, especially
the earth’s magnetic field.
Magnetostriction
The phenomenon of
change in shape and density of a substance, especially a ferromagnetic
substance, when exposed to a magnetic field is called magnetostriction.
Magnification
The apparent
enlargement of an object by an optical instrument is called magnification.
