2018 Cambridge International AS & A level May June Physics Paper 11 Q. No. 22 (9702/11/M/J/18) by Sajit Chandra Shakya from Nepal Chapter - WAVES A longitudinal wave has vibrations parallel to the direction of transfer of energy by the wave. The wave can be represented on a graph showing the variation of the displacement of the particles with distance from the source. Which point on the graph is the centre of a compression?