Melde’s Apparatus

Melde’s Apparatus is a simple way to introduce students to the concept of standing waves. The apparatus consists of a string and an oscillator to generate different frequencies. Melde’s experiment is ideal for studying the behaviour of standing waves. Supplied with accessories like pulley and clamp, scale pan and cord.
This apparatus is used to show the effects of vibrations in a stretched cord and can also be used to investigate the relationship between frequency, tension and density.

The provision of electrical contacts opened and closed by the vibrating armature allows the apparatus to be used as a high-speed changeover switch. It comprises a thin steel rod armature mounted in a clamp formed by a pair of 4mm socket terminals to adjust its free length as desired.
An AC energizing coil surrounds the armature, and a permanent magnet provides the necessary magnetic polarization. The free end of the armature, equipped with a small boss and clamping screw for attachment of the cord, also serves as the moving contact when the apparatus is operating as a changeover switch.
The complete apparatus is mounted on a box-type base.