mapping of magnetic field due to a bar magnet by use of magnetic compass
Answers
hey sakna here
The electric eld, ~E, and the magnetic eld, ~B, are
two examples of what are termed vector elds,
quantities which have both magnitude and direction
(hence are vectors) that can be assigned to every
point in a region of space. When you studied the
electric eld you learned that the magnitude of the
eld at a point was related to the amount of electric
force experienced by an electric charge located
somewhere in the eld. The direction of the eld was
given by the direction of the force (if the charge was
positive). The magnetic eld is dened in a similar
fashion, in terms of the magnitude and direction of a
force an (hypothetical) isolated magnetic element.
Measurement of the electric eld, in a quantita-
tive manner, is rather dicult. Nearby materials,
including the humidity in the air and even you,
the experimenter, can distort the measurements.
Fortunately, measurements of the magnetic eld
aren't nearly so dicult. The instrument needed
to determine the direction of the eld is a simple
compass. Determining the magnitude is a bit more
of a challenge. The advantage is that only nearby
magnetic materials (iron, steel, etc.) will signicantly
distort the eld. It is reasonably easy to arrange
an experimental space free enough of these kinds of
materials to permit good measurements.
One agent of distortion is not so easy to eliminate|the magnetic eld of the Earth itself. It is possible to
produce localized magnetic elds that, at least within a limited region of space, are much stronger than the
Earth's eld such that the distortion is minimized. We can also use the Earth's eld as a sort of comparison
standard, measuring the strength of a given magnetic eld in comparison (ratio) to that of the Earth.
Direction of the magnetic eld
Magnetic elements (poles) appear in pairs, labeled north poles and south poles. When a magnet (which
possess a north and a south pole on opposite ends) is suspended and allowed to swing freely, it will align
itself with the Earth's magnetic eld in such a way that the north pole of the magnet points generally in a
northerly geographic direction. Similarly to electrostatics, in magnetism opposites attract, and this means
that somewhere near the North Geographic Pole (where Santa lives) is located a South Geomagnetic Pole.
The actual position of the geomagnetic pole in the northern hemisphere is somewhere in the vicinity of
Hudson Bay, in Canada. The location is not constant, and there is a slow drift over the years. In fact the
poles periodically reverse direction, but the next reversal is not expected for thousands of years, so don't
throw away your compass yet.
I-1
By agreement, scientists dene the direction of a magnetic eld as being in the direction of the force that
would be exerted on a north magnetic pole located in the eld. This means that the direction of the eld
is very easily found by noting the direction that the south seeking end (usually marked in red, or with an
arrowhead) of a compass points. If you put your compass near the north magnetic pole of your bar magnet
(marked with the N), the north seeking end of the compass points away from the pole. If you put your
compass near the south magnetic pole of your bar magnet (marked with the S), the north seeking pole of
the compass points toward the pole. As a result, magnetic eld lines should point away from magnetic
hope it help plz mark as brainliest