The compelling case of the magnetic damped pendulum for undergraduate laboratories

Abstract

A damped harmonic oscillator is an important theoretical construct that is part of a typical undergraduate curriculum. While the theory is straightforward, an experiment in undergraduate settings, where the theory can be quantitatively verified, is not. I describe a practical realisation of a damped harmonic oscillator in the form of simple pendulum having a magnetic bob and an eddy current brake effected by a metal plate in its vicinity. This set-up has a simple way of controlling damping and yields observations that are amenable to a rigorous analysis. The simplicity of the set-up makes it easy to scale it up in numbers at a low cost and with minimal effort.