Physics Investigatory

YOUNG'S DOUBLE SPLIT EXPERIMENT  AND EFFECT OF DIFFRACTION IN INTERFERENCE

Student Profile  Name : Syed Aslah Ahmad Faizi Class :  XII Section :  A Class Roll No. : 20 Board Roll No. : Topic : Interference and Diffraction of Light Submitted to : Mr. Harshit Gera Date of Submission :

2018

15 January,

Signature of Student Signature of Teacher

Certificate This is to certify that Syed Aslah Ahmad Faizi of Class XII-A has successfully completed the research on the project

Young's Double Split Experiment And Effect Of Diffraction In Interference under the guidance of

Mr. Harshit Gera (Teacher) during the year 2017-18 in

 partial fulfillment fulfillment of physics physics practical examination examination conducted by CBSE, India.

Signature of Subject Teacher

Signature of Examiner

Stamp of School

 Acknowledgement I would like to express my special thanks and gratitude to my physics teacher Mr. Harshit Gera for his invaluable advice and guidance.

I would also like thank Mrs. Sarita Madhok, CEO of the school, for giving me the golden opportunity to conduct and present my experiment on the topic

Young's Double Split Experiment And Effect Of Diffraction In Interference. Lastly I would like to thank my family for supporting me in completing my experiment.

Index             

Student Profile Certificate Acknowledgement Introduction Aim Theory Apparatus Procedure Observation Calculation Result Sources of error Bibliography

Introduction |Young's Double Slit Experiment| Thomas Young, an English physician, first conducted the double slit experiment in 1801. In this experiment light was passed through two slits and an interference  pattern was observed on a screen placed a few metres away. In order to interfere the lights from the slits slits must be coherent. coherent. The wavelength and frequency frequency is of the  pattern as shown shown in fig.(i).

|Single Slit Diffraction| Light is supposed to travel in a straight line. But like sound, when it approaches a  barrier which of the same order as its wavelength, i.e., a few tenths of a millimetre it tends to bend around it. This can be seen by doing a slit experiment. When light is passed through a single slit a diffraction pattern can be observed. The wavelength and amplitude is of the pattern as shown in fig.(ii).

|Diffraction in Interference| When a double slit experiment is actually done the interference pattern observed is actually different than the one shown in fig.(i). That is mainly because of the fact that light also diffracts individually from each slit thus forming a different interference pattern. The pattern formed in of the interference amplitude enveloped inside the diffraction amplitude as shown in fig.(iii).

 Aim To perform Young's double slit experiment and find the fringe-width of the interference bands.

Theory