This work presents an experiment suitable for intermediate laboratory instruction, which is based on the forced damped oscillations of a magnetic needle. This allows the observance of a resonance phenomenon, which occurs when the frequency of the time dependent magnetic field matches the frequency of free oscillations of the compass needle that depends on the magnetization and moment of inertia of the needle. The compass needle oscillations were monitored using a Hall sensor and a PC. Theory and experiment were compared using a Fourier analysis of the data. The results are in good agreement with the theoretical expectations.
