Concepts of Physics

IIT JEE Physics (1978-2018: 41 Years) Topic-wise Complete Solutions

Visualize Wave Motion


To demonstrate various properties of wave motion.


A wave is an oscillatory disturbance traveling through a medium without change of form. The medium should be elastic, possess inertia and frictional resistance should be small.

The waves in which the particles of the medium oscillates in a direction perpendicular to the direction of propagation of waves are called transverse waves. The medium is divided into crests and troughs.

The waves in which particles oscillates in a direction parallel to the direction of propagation of the waves are called longitudinal waves. The medium is divided into compression and rarefaction.



The live model is made up of straws and beads. This model is used to explain concept of wave motion, reflection of wave from denser medium, wavelength etc. The movement of disturbance (wave) can be easily seen. Also, it shows how speed of sound increases with increase in tension.

This experiment can be extended to show effect of mass per unit length on the speed of the wave. In one model, use empty straws and in second model, use bicycle spokes within the straws to increase mass per unit length.