Magnetic Fields
Magnetic Fields
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A magnetic field is a region of space where one of the following experiences a force:
Magnetic fields are INVISIBLE, but they can be represented on diagrams using FIELD LINES.
Magnetic Field lines are lines with ARROWS that always point:
This is because the direction of the magnetic field at any point is given by the direction of the FORCE that would act on another NORTH pole placed at that point.
The CLOSER the field lines are, the STRONGER the field at that point.
The magnetic field around a BAR MAGNET looks like this:
The field lines are the CLOSEST near the POLES of the magnet, which shows that the field is the STRONGEST at those points.
Magnetic field lines CANNOT be seen, but we can plot their patterns by using a COMPASS.
A magnetic compass contains a small bar magnet which lines up with any magnetic field that it is placed within.
The Earth itself has its own magnetic field, so the needle of a compass points in the direction of the Earth’s magnetic field when placed away from any magnets.
If it is placed CLOSE to another magnet, it lines up in the direction of the MAGNET’S field instead of the Earth's.
We can use a compass to plot the pattern of a MAGNETIC FIELD by carrying out the following steps:
STEP 1: Place a bar magnet on a piece of paper and DRAW a DOT near the corner of the magnet.
STEP 2: Place a compass next to the dot and DRAW a SECOND DOT in the direction that the compass points.
STEP 3: Move the compass at the position of the SECOND DOT and draw a THIRD DOT in the direction that the compass points.
STEP 4: Repeat this process and JOIN the dots with a smooth curve to reveal a FIELD LINE. The direction of the compass gives the DIRECTION of the FIELD.
STEP 5: REPEAT this process several times to reveal more FIELD LINES.
A magnetic field is a region of space where one of the following experiences a force:
Magnetic fields are INVISIBLE, but they can be represented on diagrams using FIELD LINES.
Magnetic Field lines are lines with ARROWS that always point:
This is because the direction of the magnetic field at any point is given by the direction of the FORCE that would act on another NORTH pole placed at that point.
The CLOSER the field lines are, the STRONGER the field at that point.
The magnetic field around a BAR MAGNET looks like this:
The field lines are the CLOSEST near the POLES of the magnet, which shows that the field is the STRONGEST at those points.
Magnetic field lines CANNOT be seen, but we can plot their patterns by using a COMPASS.
A magnetic compass contains a small bar magnet which lines up with any magnetic field that it is placed within.
The Earth itself has its own magnetic field, so the needle of a compass points in the direction of the Earth’s magnetic field when placed away from any magnets.
If it is placed CLOSE to another magnet, it lines up in the direction of the MAGNET’S field instead of the Earth's.
We can use a compass to plot the pattern of a MAGNETIC FIELD by carrying out the following steps:
STEP 1: Place a bar magnet on a piece of paper and DRAW a DOT near the corner of the magnet.
STEP 2: Place a compass next to the dot and DRAW a SECOND DOT in the direction that the compass points.
STEP 3: Move the compass at the position of the SECOND DOT and draw a THIRD DOT in the direction that the compass points.
STEP 4: Repeat this process and JOIN the dots with a smooth curve to reveal a FIELD LINE. The direction of the compass gives the DIRECTION of the FIELD.
STEP 5: REPEAT this process several times to reveal more FIELD LINES.
