Hollow Prism - Physics Investigatory Project Class 12 CBSE

KENDRIYA VIDYALAYA No. 2,

Pondicherry University Campus, Kalapet, Puducherry-14

PHYSICS INVESTIGATORY PROJECT

2013-‘14

DETERMINATION OF REFRACTIVE INDICES OF

VARIOUS LIQUIDS USING A HOLLOW PRISM

Guided by,

Submitted by,

Class XII

BONA FIDE CERTIFICATE

It is hereby to certify that, the original and genuine investigation

work has been carried out to investigate about the subject matter

and the related data collection and investigation has been

completed solely, sincerely and satisfactorily done by

NAME of Class XII, Kendriya Vidyalaya No.2, Pondicherry-14,

regarding the project titled, “REFRACTIVE INDICES OF VARIOUS MEDIUMS”

Signature of the Guide Principal’s Signature

Submitted for ALL India SENIOR SECONDARY

EXAMINATION held on _____________ at KENDRIYA

VIDYALAYA No.2, PONDICHERRY.

Internal Examiner External Examiner

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, Teacher name 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,

Mr.principal, 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

Apparatus Required

Theory

Procedure

Observations

Conclusions

Precautions

Bibliography

Aim

To find out the refractive indices of different liquids using a

hollow prism

Apparatus Required

Hollow glass prism

Various liquids like water, carbon disulphide, benzaldehyde

etc.

Bell pins

Drawing board

Theory

A prism is a

transparent

optical element

with flat,

polished

surfaces that

refract light.

Prisms can be

made from any

material that is

transparent including glass, plastic and fluorite. A prism can be

used to break light up into its constituent spectral colors. Prisms

can also be used to reflect light, or to split light into components

with different polarizations.

The refractive index of the liquid

Is given by the formula:

U=sini/sinr=sin((a+d)/2)/sin(a/2)

Where,

U=refractive index of the liquid.

a= the angle of minimum deviation

d=angle of prism

i=angle of incidence

r=angle of refraction

Procedure

Fix a white sheet of paper on the drawing board with help

of drawing pins.

Keep the prism and mark the outline of it as ABC.

Drop a normal PQ on the side AB.

Draw the angle of incidence in accordance with the normal

PQ and place 2 pins so that they appear to be in the straight

line.

Place the prism filled with given sample of liquid ,on the

marked outline ABC.

Now take the pins and place them on the side AC so that all

the 4 pins appear to be in same line.

Remove the prism and draw the line joining the points so

obtained.

Mark the diagram as shown in the figure.

Repeat this with different liquids and different angle of

incidence.

Observation

Benzaldehyde

S.no a º(angle of prism) i º (angle of incidence) d º (angle of deviation)

1 60 30 45

2 60 35 42

3 60 37.5 40

4 60 39 42

5 60 40 45

U=sin((60+40)/2)/sin(30)

= 1.504

Water


1 60 30 25

2 60 35 22

3 60 40 20

4 60 45 22

5 60 50 25

6 60 55 28

U=sin((60+22)/2)/sin(30)

= 1.306

Dil. Sulphuric Acid


1 60 20 33

2 60 30 30

3 60 35 25

4 60 40 29

5 60 45 30

U=sin((60+25)/2)/sin(30)

= 1.351

Conclusion

Refractive indices at room temperature:

Benzaldehyde

o Actual: 1.546

o Experimental: 1.504

o

Water

o Actual: 1.33


o

Dil . Sulphuric acid

o Actual: 1.355


Hollow Prism - Physics Investigatory Project Class 12 CBSE

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