Measuring Magnetic Fields
1. Problem:
If I use different types of magnet how would it affect the magnetic field?
2. Background Research:
Earth’s magnetic field: the Earth’s magnetic field has a North & South Pole. It
reaches 36,000 miles into space. Earth has the strongest magnetosphere out of
all the rocky planets, it’s North and South poles reverse at irregular intervals.
Magnetic force: opposite poles attract, on the other hand two ends of a magnet
with the same polarity CANNOT stick together.
Magnetic field: there are two sides on a magnet; one of them is called the positive
& the other is negative, the magnetic flow comes from the (+) pole to the other.
Magnetism forces small pieces of iron to line up in the direction of the magnetic
force points.
Eg. If you put a compass neede that points north near a bar magnet it will turn
south.
In other words magnetic force is therefore a magnetic field. It is often stronger
when the lines of force come together and weakest when farther apart.
So if the magnet is weak the magnetic field would be weak too, thus making it
smaller.
Bibliography:
‘The Earth’s Magnetic Field’ online (available)
http://windows2universe.org/Earth/Magnetosphere /overview.html
Wednesday, October 10th 2012
‘The Force of Magnetism’ online (available)
http://www.windows2universe.org/physical_science/magnetism/magnetic_fiel
d.htmlWednesday, October 10th 2012
‘The Magnetic Field’ online (available)
http://www.windows2universe.org/physical_science/magnetism/magnetic_fiel
d.html Wednesday, October 10th 2012
3. Hypothesis: If we use the smallest magnet (aka the oblong-shaped magnet)
then the bigger the magnetic field would be because the north and south pole
of the magnet AREN’T further apart.
4. Variables:


Independent variable: type of magnet (oblong shaped, bar and
horseshoe magnet)
Dependant variable: size of magnetic field

Controlled variable: amount of iron powder used for each variable,
heigh the iron powder is dropped from (20 cm), the same frame
used to hold the magnet in place and measure the magnetic field
5. Procedure:
 1. Hold one of the magnets from above underneath the frame.
 2. Scoop 1x of the iron powder onto an UHU stick-glue lid.
 3. Measure 20 cm in height before dropping iron powder over the area of
which the magnet is placed under.
 4. Measure the length and width of magnetic field.
6. Data:
1st Trial:
Type of Magnet
Bar Magnet
Oblong shaped magnet
Horseshoe magnet
Qualitative data
Thick amount of iron
powder, shape can be
distinguished.
Not very distinguishable,
its not very thick OR thin
either.
Very distinguishable, thin
BUT thick in some parts.
Quantitative data
4 mm thick (0.4 cm)
Qualitative data
Thick and easily
distinguished
Looks like a wobbly oval,
fairly thick amount of
iron powder.
1 cm length & 2 cm width
Quantitative data
5 cm (length) & 3 cm
(width)
3 cm’s thick (since this is
an oblong it does not
have a length OR width)
Thin and distinguishable,
the iron powder looks a
bit spiked around the
edges.
1 ½ cm thick (1.5 cm)
3 mm thick (0.3 cm)
2nd Trial:
Type of magnet
Bar magnet
Oblong shaped magnet
Horseshoe magnet
7. Results:
Based on my first experiment the bigger (and longer) the magnet the bigger the
magnetic field.
The horseshoe magnet was curved so if the magnet was straight ir would have a
wider width.
It doesn’t matter how big the magnet is. The only thing that matters based on my
experiment conducted is the strength of magnet, which wakes the oblong Magnet
the strongest.
7. Conclusion:
Even though my hypothesis was correct the theory behind it wasn’t. I believe
that in my 2nd trial the truly strongest magnet was the oblong magnet because it
had a surprisingly strong magnetic field that didn’t have anything to do with it’s
south and north pole. So the magnet with the strongest magnetic field was the
oblong magnet.
Originally my group wanted to do the terrabagga activity which involved
crumpling a paper bag over a bar magnet attached to a battery and measuring
the magnetosphere. However the results were poorly and the truth is there was
no effect so we weren’t able to obtain any data.
There were a few things gone wrong with our experiment. The iron powder I
collected weren’t soft enough so they weren’t strong enough to hold onto the
magnet and I think the paper bag material was too thick. The truth is, we even
had no idea how to measure the experiment.
Nevertheless, we decided to do a simpler version of our experiment. While the
girls crushed the iron powder with the batteries (we didn’t really need them) the
boys constructed a frame made out of a cardboard box lid and pasted a paper in
the center of the frame. When all was done we tested out experiment and it
worked. The second trial was to make sure we had the correct data and we
attempted to go in-depth. For further study we would’ve studied the properties
of the iron powder if we had had the time to.
We’re very happy that out experiment had finally worked out for us, anyways.