ROSE PUBLIC
SCHOOL, SULIALI
INVESTIGATORY PROJECT 2024-25
PHYSICS PROJECT REPORT
Submitted to
MR. ATUL SHARMA
Submitted by
ADITYA RANA (ROLL NO. )
CERTIFICATE
This is to certify that
ADITYA RANA
has successfully completed his
Physics project titled REFRACTIVE
INDEX OF WATER AND OIL under
the supervision and guidance of
Physics Teacher in the partial
fulfillment of the Physics practical
assessment conducted during the
academic year 2024-2025.
Examiner Teacher
INVESTIGATORY PROJECT 2024-25
ACKNOWLEDGEMENT
I would like to express my immense gratitude
to my chemistry teacher MR. ATUL SHARMA
for the help
and guidance he provided for completing this
project.
I also thank my parents who gave their ideas
and inputs in making this project. Most of all I
thank our school management, for providing
us the facilities and opportunity to do this
project.
Lastly, I would like to thanks my classmates
who have done this project along with me.
Their support made this project fruitful.
—ADITYA RANA
INVESTIGATORY PROJECT 2024-25
INDEX
Sr. No Content Page
1 Certificate 01
2 Acknowldgment 02
3 Index 03
4 Aim 04
5 Introduction 05
6 Requirements 06
7 Diagrams 07
8 Procedure 08-10
9 Observations 11-12
10 Calculations 13
11 Results 14
Precautions and
12 15
sources of error
13 Bibliography 16
INVESTIGATORY PROJECT 2024-25
AIM
To find the refractive indexes of
(a) water
(b) oil
using a plane mirror, an equi-
convex lens, and an adjustable
object needle.
INVESTIGATORY PROJECT 2024-25
INTRODUCTION
INVESTIGATORY PROJECT 2024-25
REQUIREMENTS
1. Convex Lens
2. Plane Mirror
3. Water
4. Oil
5. Clamp Stand
6. An Optical Needle
7. Plumb Line
8. Knitting Needle
9. Half Meter Scale
10. Glass Slab
11. Spherometer
INVESTIGATORY PROJECT 2024-25
DIAGRAMS
INVESTIGATORY PROJECT 2024-25
PROCEDURE
(a) For focal length of convex lens:
1. Find the rough focal length of the
convex lens.
2. Place a plane mirror on the horizontal
base of the iron stand and then a convex
lens on the plane mirror.
3. Hold the needle in the clamp stand and
adjust its position on the stand such that
there is no parallax between tip of the
needle and its image.
4. Measure distance between tip and
upper surface of the lens by using a
plumb line and half meter scale. Also
measure the distance between tip of
needle and upper surface of the mirror.
Take the mean of the two readings. This
means distance will be equal to the focal
length of the convex lens (f1)
INVESTIGATORY PROJECT 2024-25
( b ) For focal length of combination:
5. Put a few drops of the water on the
plane mirror and put the convex lens
over it with its same face above as
before. The water spreads in a form of
layer and acts like a Plano-concave
lens.
6. Repeat the steps 3 and 4 to
determine the equivalent focal length
of the combination.
7. Record the observation.
8. Repeat the steps 5, 6, 7 for other
transparent liquid (oil).
For radius of curvature of convex lens
surface:
9. Determine the pitch and the least
count of the spherometer.
10. Remove the convex lens and dry it
completely. Put the spherometer on
this lens surface
INVESTIGATORY PROJECT 2024-25
11. All the three legs of the
spherometer should be placed
symmetrically on the lens and
adjust the central screw tip to touch
the surface of the lens.
12. Remove the spherometer from
the surface of the lens and place on
the plane mirror surface and record
the
reading.
13. Repeat the steps 10 and 11 three
times.
14. Obtain the impressions of the
three legs of the spherometer on a
paper and mark them and their
average distance.
INVESTIGATORY PROJECT 2024-25
OBSERVATIONS
INVESTIGATORY PROJECT 2024-25
INVESTIGATORY PROJECT 2024-25
CALCULATIONS
INVESTIGATORY PROJECT 2024-25
RESULTS
The refractive index of
water is µ1 = 1.0831
The refractive index of oil
is µ2 = 1.2886
INVESTIGATORY PROJECT 2024-25
PRECAUTIONS
&SOURCES OF ERROR
The plane mirror should be clean and fully
shining.
The liquid used should be transparent.
Parallax should be removed tip to tip.
The eye should be about 30 cm from the
needle when removing parallax.
Only a few drops of liquid should be used to
create a thin layer.
The legs of the spherometer should be
vertical.
The center leg of the spherometer should
turn in one direction only.
Sources of Error:
The liquid may not be completely
transparent.
Parallax may not be fully removed.
The spherometer legs may not be placed
symmetrically on the surface of the convex
lens.
The tip of the central screw may not touch
the surface of the lens or mirror.
INVESTIGATORY PROJECT 2024-25
BIBLIOGRAPHY
HELP FROM INTERNET
HELP FROM TEACHERS
NCERT TEXTBOOK
NCERT Physics Lab Manual
www.google.com
www.scribd.com
www.wikipedia.co
INVESTIGATORY PROJECT 2024-25
