Objective: Measurement and analysis of forced harmonic rotary oscillation
Pohl’s wheel or rotating (torsional) pendulum allows for the investigation of forced harmonic rotary oscillation. For this purpose, the oscillating system is connected to an excitation linkage which is driven by an adjustable-speed DC motor so that the restoring spring periodically extends and compresses. In this experiment the amplitude is measured as a function of the excitation frequency for various degrees of damping and the phase shift between the excitation and the actual oscillation is observed.