Reflection of straight and circular waves occurs when waves meet circular or straight reflectors.
When plane waves hit a surface at an oblique angle, they are reflected. This reflection follows the laws of reflection. All waves can be reflected.
Water waves are reflected from obstacles in their paths the same way as light and sound waves. All reflections obeys the laws of reflection.
See the figure below.
The laws of reflection states that:
- The angle of incidence i equals the angle of reflection r.
- The incident ray, reflected ray, and normal at the point of incidence all lie on the same plane.
Reflection of waves obeys the laws of reflection.
Plane waves normal to the reflecting surface
Plane waves incident onto a straight reflector at 90o .to the surface will be reflected such that they are perpendicular to the reflecting surface. see the figure below:
straight and circular waves: reflection of plane waves by curved reflectors
When plane waves falls onto a concave reflector, they converge to a point in front of the reflecting surface. This is the same way all rays of light parallel and close to the principal axis converge after reflection. The plane waves will be reflected as circular waves that seems to change direction after the converging point. see the figure below:
straight and circular waves: plane waves incident to convex(diverging) reflector
When plane waves meets a convex reflector. they are reflected such that they appear to diverge diverge. from a point behind the convex surface. The waves reflected from convex reflector has virtual principal focus.
circular waves against a straight reflector.
Circular waves incident to a straight reflector will be reflected as circular waves. These waves seem to have a converging point behind the plane reflector. see the figure below:
circular waves incident to the concave reflector straight up and moves as plane waves after reflection. See the figure below.
Related pages
- Thin Lenses
- Exam questions on waves
- Calculating the wave speed
- Phase and Phase Difference
- Electromagnetic waves
- Properties of waves