The advantages of using a d’Arsonval galvanometer to demonstrate forced, damped simple harmonic motion in a laboratory course are greatly enhanced if the deflection of the galvanometer can be recorded as a function of time. This is easily accomplished by modulating the radial magnetic field in which the galvanometer coil moves at a frequency too high to produce a response in the galvanometer. A signal proportional to the angular deflection of the coil is then induced in the coil, and may be amplified, rectified, and recorded. A few sample results obtained in this way are given.

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