magnetic compass |
an instrument that shows direction relative to the earth's magnetic field, usu. by means of a magnetic needle mounted on a pivot. |
magnetic equator |
an imaginary line circling the earth near the equator, composed of points where a magnetic needle does not dip because the lines of magnetic force parallel the earth's surface. |
magnetic field |
a region of space in which a magnetic force occurs, esp. as a result of electrical current or the motions of charged particles such as electrons. |
magnetic flux |
the total number of lines of induction moving through a specific area in a magnetic field. |
magnetic mine |
a marine mine designed to explode when its magnetic needle responds to the mass of a nearby ship. |
magnetic moment |
the ratio that expresses the strength of a particular source of magnetic field. [2 definitions] |
magnetic needle |
a thin magnetized bar of steel situated within an instrument, such as a compass, so that it indicates the direction of the earth's magnetic poles. |
magnetic north |
the northern direction indicated by a magnetic needle, in line with the earth's magnetic pole but usu. not true north. |
magnetic pickup |
a phonograph pickup in which vibrations of the stylus are received by a coil in a magnetic field and thus converted to electrical current. |
magnetic pole |
either of the apparent poles of a permanent magnet, at which the lines of magnetic force seem to converge. [2 definitions] |
magnetic recording |
the process or product of recording a series of electrical signals onto a magnetizable surface, esp. used for audio, visual, and computer data. |
magnetic resonance imaging |
a non-invasive medical imaging technology using radio waves and powerful magnetic fields to make the interior of the human body visible in three dimensions and in real time.(abbrev.: MRI) |
magnetics |
(used with a sing. verb) the branch of physics concerned with magnets and magnetism. |
magnetic storm |
a temporary widespread disturbance of the earth's magnetic field, caused by unusual solar activity. |
magnetic tape |
a plastic tape coated with magnetic iron oxide, used to store recorded material. |
magnetic wire |
a thin wire made of a ferromagnetic alloy, used to store recorded material. |
magnetism |
the qualities and properties associated with magnets; ability to attract. [3 definitions] |
magnetite |
a black, naturally occurring oxide of iron that is attracted to magnets and is important commercially as a source of iron. |
magnetize |
to cause to become a magnet. [2 definitions] |
magneto |
a device for producing an electric current, consisting of a coil of wire that rotates within the force field of a permanent magnet. |
magnetoelectric |
of, indicating, or relating to electricity produced by magnets or magnetic fields. |