Whenever a mirror (whether a plane mirror or otherwise) creates an image which is virtual, it will be located behind the mirror where light does not really pass.
Away; Towards; Towards
The use of a long strand of plastic (or other material such as glass) to pipe light from one end of the medium to the other is the basis for modern day use of optical fibers . Optical fibers are are used in communication systems and micro-surgeries. Since total internal reflection takes place within the fibers, no incident energy is ever lost due to the transmission of light across the boundary. The intensity of the signal remains constant.
REFLECTION ANDREFRACTION 1
The Properties of Light Linear Propagation Refraction Reflection Diffraction Polarization 2
The Characteristics of Images TYPE ORIENTATION SIZE 3
TYPE OF IMAGE Real vs Virtual Real Images can be seen on a piece of paper or screen placed because the focal point is in front of the mirror or behind the lens. Virtual Images can not be seen on a piece of paper or screen, because the focal point is behind the mirror or in front of the lens. Virtual images are images which are formed in locations where light does not actually reach; it only appears to an observer as though the light were coming from this position. 4
ORIENTATION OF IMAGE Inverted vs Upright Inverted images are upside-down. Upright images are right-side up. 5
SIZE OF IMAGE Smaller, Larger, or Same Size Smaller Images are reduced in size compared to the actual object. Larger Images are enlarged in size compared to the actual object. Same Size Objects are unchanged in size compared to the actual object. Size is also discussed quantitatively in terms of Magnification. 6
Magnification (m)The ratio of the size of the image to the size of the actual object. The Magnification equation: m = hi/ho = - di/do hi is the height of the image, ho is the height of the object, do is the distance of the object from the lens or mirror, di is the distance of the image from the lens or mirror. 7
ReflectionLight follows the same law of reflection as all other waves.Both angles are measured from the normal to the surface at the point of incidence.Glare- bright light that reflects to your eyes from the surface of smooth objects 8
Plane Mirrors Plane mirrors are uniformly flat. The image is sent back virtual, erect, same size, and laterally inverted. 9
DEFINATIONSPrincipal Axis: the straight line perpendicular to the surface ofthe mirror at its center.Focal Point: the location where the parallel rays of light fromthe source meet, or converge.Focal Length: the distance from the Focal Point to the mirroralong the Principal Axis.Center of Curvature: twice the distance of the focal point tothe mirror surface. 11
Snell’s Law A ray of light bends in such a way that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant. This constant is called the index of refraction, n 15
Criteria for T.I.R.1. Light must pass from a more optically dense to less optically dense medium.2. There are only specific angles of incidence, called the critical angle, which is different for each medium. To find the critical angle, use Snell’s Law, substituting 90º for θr. 16
An Application of T.I.R.Fiber optics. Telephone, radio,video, and television signals can now be sent with light beams rather than electric currents. This is more energy-efficient. 17