Earth's Magnetic Field
Purpose
Demonstrates Faraday's law by detecting the EMF induced when a large wire loop is rotated like a jump rope through Earth's magnetic field (~50 μT). Students see that even a very weak field produces measurable voltage when flux changes rapidly.
Figure 1:
Oscilloscope in roll mode displaying the flat baseline before rotation. The bundled wire loop ("jump rope") is visible on the right.
Figure 2:
Rotating the wire loop like a jump rope produces regular voltage peaks on the oscilloscope, corresponding to maximum rate of flux change.
Figure 3:
Two sequential traces in Roll mode show the repeatable induced EMF signal. Whether peaks appear above or below the baseline depends on the rotation direction.
Demo Apparatus
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