RANI LAXMI BAI MEMORIAL SCHOOLSECTOR 14, VIKAS NAGAR, LUCKNOW NAME :RICHA SINGHCLASS :XII-BROLL NO. :SUBJECT : PHYSICS MODEL : KALEIDOSCOPE SUBJECT : MRS. DEVINA TIWARI TAECHER

BONAFIDE CERTIFICATE

This is to certify that of class XII,board roll no:has made the model of KALEIDOSCOPE which is a bonafide record of the work carried out independently and systematically, by her under my guidance and supervision.

TEACHER: MRS. DEVINA TIWARI DATE: SIGANATURE:

ACKNOWLEDGEMENT

I wish to express my deep gratitude and sincere thanks to our Principal, Mrs.Sita Sethi, Rani Laxmi Bai Memorial School, Sector 14, Vikas Nagar, Lucknow, for her encouragement and for all the facilities that she provided for this project work. I sincerely appreciate this magnanimity by taking me into her fold for which I shall remain indebted to her. I extend hearty thanks to Mrs.DEVINA TIWARI,my physics teacher, who guided me to the successful completion of this project. I take this opportunity to express my deep sense of gratitude for her valuable guidance, constant encouragement, constructive comments, sympathetic attitude and immense motivation, which has sustained my efforts at all stages of this project work.I would also like to thank my parents and my groupmates for their undivided support and help.

KALEIDOSCOPE IntroductionLike a microscope or telescope, the optics in a kaleidoscope are used to enhance our vision in some way. Vision depends on light, and optics are used to control light by reflecting or bending it so that we can see in different ways. Kaleidoscopes use mirrors to reflect light into beautiful shapes and patterns.A kaleidoscope is an optical device used for the illustration of the image-forming properties of inclined mirrors that have been combined. When it is rotated, it produces a succession of symmetrical designs by means of mirrors reflecting the constantly changing patterns made by bits of coloured glass at one end of the tube. Every kaleidoscope, from the simplest to the most complex, uses a prism of mirrors to generate symmetric patterns of light and color from asymmetric objects.

PRINCIPLE A Kaleidoscope operates on the principle of multiple reflection.MULTIPLE REFLECTION:-Reflection is the phenomena of bouncing of the ray of light when strike at the interface between two different mediums so that the wave returns into the medium from which it originated.Common examples include when light ray incident on the mirror, it will reflected back in the same medium. When the light ray is made to reflect at different surfaces then the phenomena of multiple reflection of light came in to play.

Multiple Mirror Systems(MULTIPLE REFLECTION)Besides right angle mirror systems, there is a wealth of other multiple mirror systems that involve two or more mirrors. If two plane mirrors are placed together on one of their edges so as to form a right angle mirror system and then the angle between them is decreased, some interesting observations can be made. One observes that as the angle between the mirrors decreases, the number of images that can be seen increases. In fact as the angle between the mirrors approaches 0 degrees (i.e., the mirrors are parallel to each other), the number of images approaches infinity.

180 - Two mirrors in a straight line reflect an object only once. 120- Two mirrors set at any angle between 180 and 90 reflect an object 2 times. As the angle approaches 90, you see one mirror reflected in the other, but you do not see additional reflected objects. 90- Two mirrors at a right angle (90) show two complete reflections and one composite reflection. An angle less than 90 shows two straight reflections and two partial reflections. 60- At 60 we see five reflections four straight and one compositeParallel- When two mirrors are parallel to each other, the number of reflections is infinite. Placing one mirror at a slight angle causes the reflections to curve.Construction:- It consists of several mirrors are placed at an angle to one another, usually 60. Typically there are three rectangular mirrors set at 60 to each other so that they form an equilateral triangle. The 60 angle creates seven duplicate images of the objects, five at 60, and 2 at 90. As the tube is rotated, the tumbling of the colored objects presents varying colors and patterns. Arbitrary patterns shows up as a beautiful symmetrical pattern created by the reflections. A two-mirror kaleidoscope yields a pattern or patterns isolated against a solid black background, while the three-mirror (closed triangle) type yields a pattern that fills the entire field.

Working:-Each of the two mirrors produces an image due to the single reflection of light off one of the mirror faces to an observer's eye. The remaining images are produced as the result of multiple reflections of light off more than one of the faces. Right angle mirrors will allow a maximum of two reflections of light from the object. But as the angle decreases, three, four, and even more reflections can occur.

Determining the image locations for such multiple mirror systems can become complicated. First determine the location of the primary images using the principle thatthe image distance to the mirror is the same as the object distance to the mirror. Each primary image forms a secondary image as a result of a double reflection. By extending one of the mirror lines, a primary image can bereflected(a geometry term, not a physics term) across the second mirror line to form a secondary image - animage of an image. As an example, consider the diagram below for an object placed between two plane mirrors that make a 60-degree angle. Images I1and I2are primary images formed by the two plane mirrors. Image I3was found byreflectingimage I2across the extension of the top mirror. And image I4was found byreflectingthe image I1across the side mirror. The process can be repeated to determine the location of an image of an image of an image.

Ray diagrams for these multiple mirror systems are drawn much like they were forright angle mirror systems. Once you have located the images, begin by drawing a line of sight towards the image; this would be the reflected ray that ultimately travels to your eye. For a secondary image, this reflected ray is associated with an incident ray that had reflected off the other face of the mirror. The law of reflection can be used to determine the direction it was traveling as it was incident upon this face of the mirror. Repeat this process to determine the point of reflections on each face, tracing the path of light back to its origin - the object itself. A completed ray diagram for a secondary image on a 60-degree mirror system is shown below.

BEAUTIFUL PATTERNS FORMED BY KALEIDOSCOPEWhen we will look through the end that has a peep hole we will observe that the colored objects on the other end will reflect off of the mirrors into star-shaped patterns. Arbitrary patterns shows up as a beautiful symmetrical pattern created by the reflections.

SOME IMPORTANT APPLICATIONS OF KALEIDOSCOPE

Applications in Industry, Business and Science

The early use of kaleidoscopes was for entertainment and the sheer enjoyment of the beautiful images. Still a worthy use today.

Utilitarian uses include incorporating kaleidoscope views and patterns into tapestries, rugs, carpets, wallpaper, fabric and more.

MEDICAL CARE

Kaleidoscopesare being incorporated into hospice and other medical care more and more. Attorneys and dentists have been known to keep them in their offices and waiting rooms to calm nervous or contentious clients. More recent research has documented the benefits of incorporating color therapy or chromotherapy intokaleidoscopeviewing. In chromotherapy, different colors have been found to be associated with various positive emotions and aid in bringing these emotions about.

CONTENTSACHNOWLEDGEMENT

INTRODUCTION

PRINCIPLE:- MULTIPLE REFLECTION MULTPLE MIRROR SYSTEM

CONSTRUCTION

WORKING

BEAUTIFUL IMAGES FORMED BY KALEIDOSCOPE

SOME IMPORTANT APPLICATIONS