physics

ACKNOWLEDGEMENT

The successful completion of any task would be incomplete without mentioning the names of those persons who helped to make it possible. I take this opportunity to express my gratitude in few words and respect to all those who helped me in the completion of this project.It is my humble pleasure to acknowledge my deep senses of gratitude to my Physics teacher, Mr. Riyaz for her valuable support, constant help and guidance at each and every stage, without which this project would not have come forth.I also register my sense of gratitude to our principal, Dr. Syed Shoukath Ali, for his immense encouragement that has made this project successful.I would also like to thank my friends and family for encouraging me during the course of this project.Last, but not the least, I would like to thank CBSE for giving us the opportunity to undertake this project.

Project Overview

Aim RequirementsIntroductionWhat Is A Prism ?How Does A Prism Work ?ProcedureObservationsConclusions Precautions And Sources Of ErrorsBibliography

OBSERVATIONS

S.noa (angle of prism)i (angle of incidence)d (angle of deviation)

160

260

360

460

560

U=


160

260

360

460

560

660

U=


160

260

360

460

560

U=

CONCLUSION

Refractive indices at room temperature:

Actual: Experimental:



procedure

FIX THE SHEET OF WHITE PAPER ON THE DRAWING BOARD WITH DRAWING PINS. PLACE THE PRISM FILLED WITH LIQUID ON THE PAPER AND TRACE ITS BOUNDARY ABC. MARK A POINT O ON ONE OF THE REFRACTING SURFACES AND DRAW A NORMAL TO THE SURFACE AT THIS POINT. DRAW A STRAIGHT LINE PQ CORRESPONDING TO INCIDENT RAY DRAWN AT A SUITABLE ANGLE WITH THE NORMAL. FIX TWO PINS P AND Q ABOUT 5CM APART ON THE INCIDENT RAY LINE AN VIEW ITS IMAGE WITH ONE EYE CLOSED FROM THE SIDE AC OF THE PRISM. FIX TWO PINS R AND S SUCH THAT THE TIPS OF THESE PINS AND THE TIPS OF THE IMAGES OF THE INCIDENT RAY PINS P Q LIE IN THE SAME STRAIGHT LINE. ENCIRCLE THE PIN PRICKS ON THE PAPER. REMOVE THE PINS P Q AND ALSO ENCIRCLE THEIR PIN PRICKS. JOIN POINTS S AND R AND PRODUCE IT BACKWARDS TO MEET THE INCIDENT RAY PQ PRODUCED. THUS, RS IS THE EMERGENT RAY CORRESPONDING TO THE INCIDENT RAY PQ. DRAW ARROW HEADS TO SHOW THE DIRECTION OF THE RAYS. MEASURE THE ANGLE OF DEVIATION WITH A PROTRACTOR AND MEASURE PRISM ANGLE.

PRECAUTIONS AND SOURCES OF ERROR

A SHARP PENCIL SHOULD BE USED.. PROPER ARROWS SHOULD BE DRAWN TO INDICATE THE INCIDENT, THE REFRACTED AND THE EMERGENT RAY.

A SMOOTH CURVE PASSING THROUGH ALL THE POINT SHOULD BE DRAWN.

THE ANGLE OF PRISM SHOULD BE USED FOR ALL OBSERVATIONS.

PINS SHOULD HAVE SHARP TIPS AND BE FIXED VERTICALLY.

VISIBILITY OF PINS MAY BE LOW FOR COLOURED LIQUIDS, THEY MAY BE ILLUMINATED BY A SOURCE OF WHITE LIGHT.

INTRODUCTION

In optics, a prism is a transparent optical element with flat, polished surfaces that refract light. The exact angles between the surfaces depend on the application. The traditional geometrical shape is that of a triangular prism with a triangular base and rectangular sides, and in colloquial use "prism" usually refers to this type. Some types of optical prism are not in fact in the shape of geometric prisms. Prisms can be made from any material that is transparent to the wavelengths for which they are designed. Typical materials include glass, plastic and fluorite.A prism can be used to break light up into its constituent spectral colors (the colors of the rainbow). Prisms can also be used to reflect light, or to split light into components with different polarizations.

WHAT IS A PRISM ?

Before Isaac Newton, it was believed that white light was colorless, and that the prism itself produced the color. Newton's experiments demonstrated that all the colors already existed in the light in a heterogeneous fashion, and that "corpuscles" (particles) of light were fanned out because particles with different colors traveled with different speeds through the prism. It was only later that Young and Fresnel combined Newton's particle theory with Huygens' wave theory to show that color is the visible manifestation of light's wavelength.Newton arrived at his conclusion by passing the red color from one prism through a second prism and found the color unchanged. From this, he concluded that the colors must already be present in the incoming light thus, the prism did not create colors, but merely separated colors that are already there. He also used a lens and a second prism to recompose the spectrum back into white light. This experiment has become a classic example of the methodology introduced during the scientific revolution. The results of this experiment dramatically transformed the field of metaphysics, leading to John Locke's primary vs secondary quality distinction.Newton discussed prism dispersion in great detail in his book Opticks. He also introduced the use of more than one prism to control dispersion. Newton's description of his experiments on prism dispersion was qualitative, and is quite readable. A quantitative were introduced in the 1980s.

HOW DOES A PRISM WORK ?

Light changes speed as it moves from one medium to another (for example, from air into the glass of the prism). This speed change causes the light to be refracted and to enter the new medium at a different angle (Huygens principle). The degree of bending of the light's path depends on the angle that the incident beam of light makes with the surface, and on the ratio between the refractive indices of the two media (Snell's law). The refractive index of many materials (such as glass) varies with the wavelength or color of the light used, a phenomenon known as dispersion. This causes light of different colors to be refracted differently and to leave the prism at different angles, creating an effect similar to a rainbow. This can be used to separate a beam of white light into its constituent spectrum of colors. Prisms will generally disperse light over a much larger frequency bandwidth than diffraction gratings, making them useful for broad-spectrum spectroscopy. Furthermore, prisms do not suffer from complications arising from overlapping spectral orders, which all gratings have.Prisms are sometimes used for the internal reflection at the surfaces rather than for dispersion. If light inside the prism hits one of the surfaces at a sufficiently steep angle, total internal reflection occurs and all of the light is reflected. This makes a prism a useful substitute for a mirror in some situations.

AIM

TO INVESTIGATE THE DEPENDENCE OF THE ANGLE OF DEVIATION, ON THE ANGLE OF INCIDENCE , USING HOLLOW PRISM FILLED WITH DIFFERENT TRANSPARENT FLUIDS.

REQUIREMENTS

DRAWING SHEET DRAWING BOARD PINS PENCIL HOLLOW GLASS PRISMS PROTRACTOR RULER

biblography

www.google.comwww.wikipedia.com

class 12 physics lab manual

physics

Documents