Physics for IGCSE & O level - Waves And Sounds (Section 5 - No. 34)
When does refraction of a wave occur?
When a wave bounces off a surface
When a wave bends around a corner
When a wave passes from one medium to another and changes speed
When two waves combine
Explication
Refraction is the bending of a wave as it passes from one medium to another due to a change in speed.