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Smartphone magnetometer experiments

7 classroom-tested activities with the free FizziQ app, for high school, middle school.

The magnetometer measures the three components of the magnetic field at the phone, in microteslas. FizziQ displays each component, the field magnitude, and a compass. Instruments in FizziQ: magnetic field (X, Y, Z and magnitude), compass, theodolite. Read the glossary entry on the magnetometer.

Each activity below has a protocol, expected results, scientific background, a printable PDF handout and a QR code that opens it directly in the app. FizziQ is free on iOS and Android, needs no account, and shows no advertising.

Activities

  1. Biot-Savart law: a coil High school 45 min

    Students measure the magnetic field of a current-carrying coil with the smartphone magnetometer in FizziQ and plot B against I to verify the Biot-Savart law.

  2. Law of sines with a theodolite High school 40 min

    Students measure the angles of a triangle in the schoolyard with the FizziQ smartphone theodolite, then apply the law of sines to calculate unknown distances.

  3. Magnetic inclination and latitude Middle school 30 min

    Middle school students record the magnetic dip angle with the smartphone magnetometer and inclinometer in FizziQ Duo mode, then calculate their magnetic latitude.

  4. Speed by magnetic markers High school 30 min

    Magnets placed along a track create peaks in the magnetometer signal of a smartphone on a moving cart; students use FizziQ to compute speed from the peak timing.

  5. Magnetic detection of objects Middle school 35 min

    Turning the smartphone magnetometer into a metal detector, middle school students locate hidden ferromagnetic objects and analyse field variations with FizziQ.

  6. Magnetic north by magnetometer Middle school 30 min

    Rotating a smartphone through 360° in FizziQ, middle school students find where the horizontal magnetic field peaks, then check that magnetic heading with a compass.

  7. Triangulation with a theodolite High school 40 min

    Using the FizziQ smartphone theodolite, students measure azimuths between four landmarks and apply the law of sines to compute every distance from one baseline.

Other sensors

accelerometer · microphone · barometer · gyroscope · light sensor · camera · GPS · external sensors