EARTH MAGNETIC FIELD Name______
This lab uses your phone and the App Phyphox or another App to measure the
magnetic field of the Earth. If you do not have a smartphone, please contact your
instructor to complete an alternative lab.
Each lab counts for 20 points and it is about 1.42% of the total grade, each little
point counts, do not miss it!
Introduction
If you want to go more in depth about the earth magnetic field, you may read interesting facts on
the NOAA website, Earth’s Magnetic Field: The Force That’s Always with You.
The Earth is surrounded by a magnetic field due to a dynamo effect at its interior. The
field is similar to the field originated by a bar magnet having the magnetic south pole
close to the geographic north pole and the magnetic north close to the geographic south
pole. Currently, the axis of the magnet is offset by about 11 degrees with respect to the
earth rotational axis.
Magnetic field is represented by field lines (in blue in the picture). As one may see in
Fig. 1, in the northern hemisphere, the magnetic field lines are pointing toward the
center of the Earth while in the southern hemisphere they are pointing away from the
center of the Earth.
At a given location, the inclination angle is the angle between the magnetic field vector
and the horizontal plane (the plane tangent to the surface of the Earth at that point). The
inclination is positive when the magnetic field points downward into the Earth and
negative when it points upward. See Fig.2 below.
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, Figure 1. The Earth magnetic field (Hyperphysics.com )
Figure 2. The B vector and the Inclination angle 𝞋 (theta)
Activity
1. On your phone, download the free App. Phyphox or any other app that would use
your phone magnetometer and give you the three coordinates of the B- field at
your location.
Image from Phyphox
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This lab uses your phone and the App Phyphox or another App to measure the
magnetic field of the Earth. If you do not have a smartphone, please contact your
instructor to complete an alternative lab.
Each lab counts for 20 points and it is about 1.42% of the total grade, each little
point counts, do not miss it!
Introduction
If you want to go more in depth about the earth magnetic field, you may read interesting facts on
the NOAA website, Earth’s Magnetic Field: The Force That’s Always with You.
The Earth is surrounded by a magnetic field due to a dynamo effect at its interior. The
field is similar to the field originated by a bar magnet having the magnetic south pole
close to the geographic north pole and the magnetic north close to the geographic south
pole. Currently, the axis of the magnet is offset by about 11 degrees with respect to the
earth rotational axis.
Magnetic field is represented by field lines (in blue in the picture). As one may see in
Fig. 1, in the northern hemisphere, the magnetic field lines are pointing toward the
center of the Earth while in the southern hemisphere they are pointing away from the
center of the Earth.
At a given location, the inclination angle is the angle between the magnetic field vector
and the horizontal plane (the plane tangent to the surface of the Earth at that point). The
inclination is positive when the magnetic field points downward into the Earth and
negative when it points upward. See Fig.2 below.
1/9
, Figure 1. The Earth magnetic field (Hyperphysics.com )
Figure 2. The B vector and the Inclination angle 𝞋 (theta)
Activity
1. On your phone, download the free App. Phyphox or any other app that would use
your phone magnetometer and give you the three coordinates of the B- field at
your location.
Image from Phyphox
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