Waves and Sound - SS2 Physics Past Questions and Answers - page 4

Reflection is the bouncing back of waves when they encounter a surface or boundary. When a wave encounters a reflective surface, it changes direction and returns to the original medium. This phenomenon is widely observed in daily life. For example, when we look into a mirror, light waves from our face are reflected off the mirror's surface and into our eyes, allowing us to see our reflection. Reflection is also utilised in various optical devices such as telescopes, periscopes, and retroreflectors. Moreover, it plays a crucial role in the functioning of radar systems and ultrasound imaging.

Refraction refers to the bending of waves as they pass from one medium to another, resulting in a change in their direction and speed. This phenomenon occurs due to the change in the wave's velocity when it encounters a boundary between two media with different refractive indices. The degree of bending depends on the angle of incidence and the refractive indices of the media involved. Refraction is a fundamental concept in optics as it governs the behaviour of light when it passes through lenses, prisms, and other optical devices. It enables the focusing of light, formation of images, and the correction of vision in eyeglasses.