Light

• Reflection is when light reverts to the same medium after it strikes a surface.
• The surface of the plane mirror that reflects most of the light incident on it is the back silvered surface.
• Plane mirror – It is highly polished and a smooth reflecting surface that is prepared from a clear plane glass sheet, which are usually thin and silvered with appropriate reflecting abrasive on one of the sides. After pasting, the glass turns opaque but because of the reflecting property of the abrasive, the plane glass sheet turns into a plane glass mirror or plane glass reflector
• Incident ray – it is the light ray that strikes a reflecting surface
• Angle of incidence – it is the angle which the incident ray makes with the normal at the point of incidence. It is denoted by ‘i’
• Angle of reflection – it is the angle made by the reflected ray with the normal at the point of incidence. It is denoted by ‘r’
• The two laws of reflection of light are as follows:

  • The angle of incidence is equal to the angle of reflection
  • The incident ray, the reflected ray and the normal at the point of incidence, all lie in the

  same plane
• The three characteristics of image formed by a plane mirror:

  • Images formed are upright or erect
  • Images formed are virtual
  • Images formed are of the same size as the object
• A ray is incident on a plane mirror. Its reflected ray is perpendicular to the incident ray.

  i=r=45°