Reflection of Waves Reflection of waves occurs when a wave strikes a reflector. The wave undergoes a change in direction of propagation when it is reflected.The incident wave is the wave before it strikes the reflector and the reflected wave is the wave which undergoes a change in direction of propagation.

Characteristics of Reflection of Waves(a) Angle of incidence = Angle of reflection(b) The incident wave, the reflected wave and the normal all lie in the same plane perpendicular to the reflecting surface.(c) Wavelength of incident wave = Wavelength of reflected waves(d) Frequency of incident wave = Frequency of reflected waves(e) Speed of incident wave = Speed of reflected waves, but in different directions

Pattern of Reflected Plane Waves(a) Plane wave approaches a plane reflector normally

Pattern of Reflected Plane Waves(b) Plane waves approach a plane reflector at an angle

Pattern of Reflected Plane Waves(c) Plane wave approaches a concave reflector

Pattern of Reflected Plane Waves(d) Plane wave incident on a convex reflector

Pattern of Reflected Circular Waves(a) Circular wave incident on a plane reflectorThe reflected wave diverges as if from image point P'.

Pattern of Reflected Circular Waves(b) Circular wave incident on a concave surfaceCircular wave is reflected as plane wave.

Pattern of Reflected Circular Waves(c) Circular wave from centre C approaches a concave reflectorCircular wave from centre of curvature, C, converges back at C after reflection.

Pattern of Reflected Circular Waves(d) Circular wave approaches a convex reflectorThe reflected wave diverges as if from image point P'.

Note:When drawing diagrams of reflected wave,(a) Draw the direction of propagation first.(b) Draw the normal to the reflector.(c) Incident angle = Reflected angle.(d) Incident wavelength = Reflected wavelength