For these measurements we need:

• Function Generator.
• Oscilloscope
• Coil to be tested
• Resistor (value depends on the coil value and frequency range)

Connect the coil with a series resistor to the function generator. Adjust the frequency until the peak-to-peak voltage over the coil is the same as the peak-to-peak voltage over the resistor. In that case “V-scope” is 50% of “V-Gen”.

The exact ratio between the generator voltage and the voltage measured by the scope over the inductor can be calculated with the following network theory:

In this formula L represent the inductance, R the resistance, and omega the radial frequency ( = 2*pi*f with f in Hz). The question now is for what frequency (Vscope/Vgen) = 0.5:

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