What is meant by the polarisation of a wave? - Leaving Cert Physics - Question d - 2016

Polarisation of a wave refers to the orientation of the oscillations of the wave in a particular direction. For instance, in the case of transverse waves, such as light waves, the vibrations are perpendicular to the direction of wave propagation. When a wave is polarised, its vibrations occur predominantly in a single plane.

In simpler terms, if we consider a light wave, polarisation restricts the vibrations to a single plane rather than allowing them to occur in multiple directions. This can be achieved through various methods such as reflection, refraction, or using a polarising filter. Overall, the concept of polarisation is crucial in understanding various optical phenomena and applications.