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www.ammhu.com A categorized blogging website and an Online Resource Centre For CBSE, RBSE, and Other State Boards — Raj Kumar Parashari, Head Science @ JPHS, Jaipur-302021
SCHOOL NAME SCHOOL NAME SCHOOL NAME
ADDRESS WITH PINCODE AND PHONE NUMBER
Submitted by Guided by
Student Name [ ]
Class With Section Teacher Name
Class Roll No. Designation
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www.ammhu.com A categorized blogging website and an Online Resource Centre For CBSE, RBSE, and Other State Boards — Raj Kumar Parashari, Head Science @ JPHS, Jaipur-302021
Board Roll No.
INDEX
1. CERTIFICATE
2. ACKNOWLEDGEMENT
3. AIM
4. APPARATUS REQUIRED
5. PRINCIPLE / THEORY
6. RAY DIAGRAMS & IMAGES
7. PROCEDURE
8. OBSERVATIONS
9. CALCULATIONS
10. RESULT
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www.ammhu.com A categorized blogging website and an Online Resource Centre For CBSE, RBSE, and Other State Boards — Raj Kumar Parashari, Head Science @ JPHS, Jaipur-302021
CERTIFICATE
This is to certify that _______________________
student of ______ school name _______, class XII Sc __
has carried out his work for the investigatory project
entitled _______________________________________
under my guidance and supervision.
Signature of the Teacher
Designation
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www.ammhu.com A categorized blogging website and an Online Resource Centre For CBSE, RBSE, and Other State Boards — Raj Kumar Parashari, Head Science @ JPHS, Jaipur-302021
ACKNOWLEDGEMENT I __________________________________ a student of
____________________________________,______________
would like to pay my sincere gratitude to my Physics teacher
Mr. __________________________ for helping and guiding
me throughout the completion of the project report. I would
like to thank Mr./Mrs. _______________________ our school
principal/Director for making school such a wonderful place of
learning. I also would like to thank Mr. ________________
our lab assistant for the timely assistant in completion of the
project.
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www.ammhu.com A categorized blogging website and an Online Resource Centre For CBSE, RBSE, and Other State Boards — Raj Kumar Parashari, Head Science @ JPHS, Jaipur-302021
AIM (i) To investigate the dependence of the angle of deviation
with the angle of incidence, using a hollow prism filled with
different liquids one by one and
(ii) to calculate their respective refractive indexes.
APPARATUS REQUIRED A hollow prism, translucent liquids (e.g., water, any oil such
as oil, kerosene oil or turpentine oil and glycerin)whose
refractive index is to be find, A laser light/ all pins,
protector, meter scale and plane sheets.
THEORY (i) When a ray of light RQ is incident on a prism of denser
medium at a certain angle of incidence, it is refracted along
QS towards the normal at the point of incidence. This ray is
then incident on the second face. Since it is traveling form
denser to rarer medium, it bends away from the normal and
emerges along ST. Angle of deviation δ is the angle between
the incident ray produced forward and the emergent ray
produced backwards. The TFK= δ is the angle of the
deviation. Ray diagram for the refraction through prism is
shown following
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www.ammhu.com A categorized blogging website and an Online Resource Centre For CBSE, RBSE, and Other State Boards — Raj Kumar Parashari, Head Science @ JPHS, Jaipur-302021
i
m
1r 2r
1P
2P3
P
4P
1N
2N
3N
i
For the refraction through the prism, the relation always
applicable is
i +e = A+ δ
where, i = angle of incidence
A = prism angle
e = angle of emergence
δ = angle of deviation
When the angle of incidence is changed, angle of deviation
also changes, which graphically is represented as follows;
(ii) From the graph it is obvious that with increase in angle
of incidence angle of deviation first decreases , takes the
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www.ammhu.com A categorized blogging website and an Online Resource Centre For CBSE, RBSE, and Other State Boards — Raj Kumar Parashari, Head Science @ JPHS, Jaipur-302021
minimum value and then increases. If m be the minimum
value of angle of deviation then, the refractive index of the
material of the given prism is given by;
mAsin
2
Asin
2
-------------- (1)
PROCEDURE
(i) Fill the hollow prism with water first.
(ii) Fix the white sheet of paper on the drawing board with
drawing pins.
(iii) Place the prism on this white sheet and mark the boundary
ABC of the prism.
(iv) Lift the prism and mark a point Q in the middle of AB.
Draw perpendicular QN1 on AB.
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www.ammhu.com A categorized blogging website and an Online Resource Centre For CBSE, RBSE, and Other State Boards — Raj Kumar Parashari, Head Science @ JPHS, Jaipur-302021
(v) Draw a line QR making an angle 35 with QN1. Fix two
office pins P1 and P2 on QR with distance more than 10cm
between P1 and P2.
(vi) Now, place the prism on its boundary ABC. Seeing through
the face AC, fix two more pins P3 and P4 in such a way that the
images of P1 and P2 are in line with P3 and P4, i.e., the feet of all
the four pins should be in a straight line.
(vii) Remove P3 and P4 and join their positions to make a line
ST. .
(viii)Produce RQ and TS so that the two meet at F.
(ix) As shown in fig, measure angle of incidence N1QR = i
and angle of deviation KFS = δ.
(x) 0Measure the value of angle of angle of deviation with the
help of protractor.
(xi) Measure the angle of prism (A) between the refracting
faces AB and AC of the prism.
(xii) Repeat this process with different value of angle i and
measure angle respectively.
(xiii)Increase the value of angle i by 5 each time.
(xiv) Record the observations in tabular form.
(xv) Plot a graph between the angle of incidence i (along x-axis)
and angle of deviation (along y-axis). This graph obtained will
be as shown in the figure below.
(xvi) Note the value of the angle of minimum deviation δm from
the graph corresponding to the lowest point of the i- curve as
shown.
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www.ammhu.com A categorized blogging website and an Online Resource Centre For CBSE, RBSE, and Other State Boards — Raj Kumar Parashari, Head Science @ JPHS, Jaipur-302021
(xvii) Repeat the experiment by replacing water in the hollow
prism by filling any type of transparent oil and then with
glycerin.
Observations:—
Liquid S. No. Angle of
Incidence(i)
Angle of
deviation( )
Water 1. 30°
2. 35°
3. 40°
4. 45° 5. 50°
6. 55° Oil 1. 30°
2. 35° 3. 40°
4. 45° 5. 50° 6. 55°
Glycerin 1. 30°
2. 35°
3. 40°
4. 45° 5. 50° 6. 55°
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www.ammhu.com A categorized blogging website and an Online Resource Centre For CBSE, RBSE, and Other State Boards — Raj Kumar Parashari, Head Science @ JPHS, Jaipur-302021
Result-
(1) The graph between i and for each liquid
shows that as the angle of incidence increases,
the angle of deviation first decreases and
attains a minimum value m and then
increases.
(2) The angle of minimum deviation from the
graph for
(i) Water-
(ii) Oil -
(iii) Glycerin –
(3) The refractive indexes of the liquids under
consideration are
(i) µWater =
(ii) µOil =
(iii) µGlycerin =
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Bibliography
1.
2.
3.
Note: — Hand written Investigatory Project
Report should be submitted. Work should be
neat and clean. Avoid unnecessary fancy
decoration of the project report.
Note: — Take readings, draw graph for each
between angle of deviation v/s angle of
incidence for each liquid. Find angle of
minimum deviation for each liquid, Do
analysis and requires calculations to complete
your project as suggested.
Note: — Learn theory, working and related
viva for board practical examination.
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Wish you all the best.
Raj Kumar Parashari
Head Science
JPHS, Jaipur