1. ACKNOWLEDGEMENT
I would like to express my sincere thanks to the Management of Ahmed Abdullah
Garib Private Industrial Training Institute for its generous assistance, sharing of
knowledge, experience, views, and suggestions and for giving me their gracious
support.
I am grateful to “MR FEROZ YUSUF SHAIKH” Principal of Ahmed Abdullah Garib
Private Industrial Training Institute for his support and encouragement at various
stages as also for providing us with required faculty.

2. SR NO. TOPIC
PAGE
NO.
01 WHEEL AND AXLE 1
02 FLOATING MAGNET 2
03 NEWTON DISC 3
04 DAY NIGHT 4
05 TRANSVERSE WAVE PENDULUM 5
06 ORGAN PIPE 6
07 BALANCING NAILS EXPERIMENT 7
08 PROJECT OF AUTOMATIC EARTHEN POT 8
10 DNA STRUCTURE 9
11 MAXWELL'S WHEEL 10
12 NEWTON’S CRADLE 11
13 JASTROW ILLUSION 12
14 GEAR TRAIN 13
15 PERCEIVING DEPTH 14
16 MINI ELECTRIC GENERATOR 15
17 CENTRIFUGAL LOAD LIFTER 16
18 DIP TUNNEL INFINITE MIRROR WALL 17
19 SEISMOGRAPHIC ALARM 18
20 REFLECTION OF LIGHT 19
21 LEVER REDUCE EFFORT 20
22 PROJECTOR USING CONVEX LENS 21
23 MAGNETIC LEVITATION 22
24 ANTI-GRAVITY DISC 23
25 WHICH ONE IS HEAVY 24
26 FORMATION OF MULTIPLE IMAGES WITH PLANE MIRRORS 25
27 ILLUSION OF 2D TO 3D 26
28 HOLOGRAM 3D MODEL 27
29 CONDUCTIVITY TEST FOR LIQUID MATERIALS 28

3. WHEEL AND AXLE
The wheel and axle is a simple machine consisting of a wheel attached to a smaller
axle so that these two parts rotate together in which a force is transferred from one to the
other. The wheel and axle both rotate at the same rate
Wheel and axle is one of the most important simple machines. Generally in wheel and axle
there are two cylinders. The larger cylinder is called wheel. Here our wheel is made of bottle
cap. For easiness we have added handle. Another cylinder is bamboo stick that works as
axle.
Like other simple machine wheel and axle also helps us to make our work easy and faster
with less effort.
1. Wheel and axle is used to pull water from well. As in our demonstration.
2. It is used in wheel of vehicles like car, bus, truck, etc .
3. Wheel and axle always makes our work easier. With less effort large load can be
moved.
4. This simple machine increase our speed or work.
5. It helps us to make us safe.

4. FLOATING MAGNET
Objective
In this science project you'll discover how to place magnets so they either attract or repel
one another and then use that information to levitate a magnet.
One of the most basic and important features of magnets is that, they always align
themselves so that one end faces the North Pole and the other end faces the South Pole,
these two ends are referred to as the north and south poles of the magnet. By aligning the
poles of two magnets in different combinations, the magnets will either be attracted, (pulled
closer to one another) or repelled (pushed farther apart from one another

5. NEWTON DISC
Introduction:
Newton disc was invented by the great scientist Isaac Newton. This experiment basically
consists of 7 colors in a single disc. These colors are rainbow colors. When the disc is
rotated, the colors fade into a white color. Appointment Thus, in simple terms, Newton
mentioned that the white light is a combination of the seven colors of the rainbow.
This whole process or result is based on the principle of dispersion of light. This also
follows a simple concept called as temporal optical mixing.
This means that when the disc moves very fast at a certain speed, the stimuli cannot he
colors, and it looks like a white light.
Conclusion:
Newton disc experiment is also called as concept of
Newton’s colour wheel theory or colour disk theory because all the seven colour are on a
single disc that are arranged as petals equally.
The perception of the colour stays for a fraction of second to the human eye. When the disc
rotates fast enough, the colour all together appear to be white.
It is based on a theory of optical mixing and additive colour theory which states that any
two colour or more colour mixed will lead to a different colour to the human eye when they
are put together.
White light compromised of all the colours of the visible spectrum.
i.e. red, orange ,yellow , green , blue, indigo , voilate

6. DAY NIGHT
WHY DO WE HAVE A DAY AND NIGHT?
Day and night occurs because the Earth is spinning on its axis.
As the Earth orbits the Sun it spins on its axis once every 24 hours. We call this time one
day.
In one day every point on the Earth's surface will come out of night, go through a day, dusk
and then into night once more.
If you were standing on the equator you would be travelling round at roughly 1600 km/hour
(1000 mph) due to this rotation. At latitude 51o N you would be moving at just over 100
km/hr (630 mph) as you have a smaller distance to travel in the same time.
Dusk is due to the sunlight filtering through the atmosphere of the Earth. On a planet or
moon with no atmosphere the transfer from day to night would be instantaneous with no
dusk.
The Sun (and planets, stars and the Moon) rise in the east and set in the west. This means
that countries further east of an observer will move into daylight first and so sunrise will be
earlier the further east you go.

7. TRANSVERSE WAVE PENDULUM
A simple pendulum consists of a relatively massive object hung by a string from a
fixed support. It typically hangs vertically in its equilibrium position. The massive object is
affectionately referred to as the pendulum bob. When the bob is displaced from equilibrium
and then released, it begins its back-and-forth vibration about its fixed equilibrium position.
The motion is regular and repeating, an example of periodic motion. Pendulum motion was
introduced as we tried to understand the nature of vibrating objects.
The Pendulum Wave is a device that provides such an opportunity. It consists of a
series of pendulum with increasing periods that when simultaneously released, produce the
effect of a changing transverse wave that cycles back to the beginning conditions

8. ORGAN PIPE
An organ pipe is a sound-producing element of the pipe organ that resonates at a
specific pitch when pressurized air (commonly referred to as wind) is driven through it.
Each pipe is tuned to a specific note of the musical scale.
The organ produces sound by forcing air through pipes or flutes of different sizes.
Air is pushed through pipes by bellows which are supplied by a fan operated by foot pedals
or electric. The organists will press the keys to open a vent so air can travel through a
particular pipe, producing the sound. All sound is caused by vibrations. The source that
sends the vibrations is disturbing the surrounding air so much that sound waves are
formed. If these vibrations reach the ear they are perceived as sound. The speed of the
vibrations is the same no matter how loud or quiet a noise is. A pure sound has three basic
properties, one of which is pitch. The pitch of a sound depends on the rate the vibrations
are made and is measured in hertz (Hz). The higher a sounds frequency then the higher the
pitch of the sound will be. The ear responds to the vibrations in the air and they are
translated into nerve signals and carried to the brain.

9. BALANCING NAILS EXPERIMENT
Aim: Determine the centre of gravity as twelve nails find precarious stability on the head of
just one nail.
Materials List
 10 Nails
 Board Acrylic
 Hole punch
1. Firmly place one nail into the center of the board. Place the block flat on a desk or
table and try balancing the remaining 9 nails on the head of the standing nail. Be
creative! But don’t cheat by using things like magnets, glue, gum, spit, etc.
NOTE: To win this challenge, all 9 nails must balance exclusively on the single
standing nail. None of the eleven nails may touch the wood block, the desk or table, or
anything else that might help hold them up. No additional equipment other than the
wood block and the nails may be used. Impossible? We’ll show you how it’s done! The
key is to arrange the nails so all of their mass is evenly distributed and they can be
supported on one point.
2. Lay any nail flat on the table with the head on either the right or left side. This is nail
#1. Hook the head of nail #2 over #1 so that it is next to the head of #1. #2 is
perpendicular to #1. Nail #3 also hooks over #1 but points in the opposite direction as
#2 and is also perpendicular to #1. The heads of #2 and #3 should be separated by
about the width of nail #1. Continue laying the nails in alternating directions, leaving
one nail aside. When you have done this, you should have five nails on one side and
four on the other.
3. Nail #11 is laid on top of all the heads but points in the opposite direction as #1. Nail
#11 rests nicely between the heads of the nails you just hooked to #1.
4. Use two hands and carefully lift all the nails by holding the ends of #1 and #11
together. Now, use the center of the group and balance all 11 nails on top of the lone
standing nail. It might take you a couple of tries, but trust us… you’ll get it!

10. AUTOMATIC EARTHEN POT
AIM: As per covid norms to Avoid physical contact like handshakes, hand holding or
hugs. Avoid touching surfaces such as table tops, chairs, door handles etc.
We have designed this earthen pot which is totally sensor based that help us to dispense
water without touching
This Earthen pot is modified by replacing the tap with circuit consisting of transistor, ir
sensor, led light and 5v dc pump which help to make automatic water dispenser.
COMPONENTS LIST:
SR.NO EQUIPMENT NAME SIZE QUANTITY
1 Earthen Pot Standard 1
2 IR SENSOR (MODULE) FC-51 1
3 TRANSISTOR TIP 32C PNP 1
4 REISISTOR 1K 2
5 DC SWITCH 1 1
6 LED LIGHT (2GREEN + 2RED) 3V 4
7 SUMBERSIBBLE WATER PUMP 5V DC 1
8 RO PIPE 14” 2METER
9 PIPE FITTING ELBOW CONNECTOR 14” 2

11. DNA STRUCTURE
DNA is a double helix.
The structure of DNA can be likened to a twisted ladder. The rungs of the ladder are made
up of "bases"
Adenine (A) is a base.
Thymine (T) is a base. Cytosine (C) is a base
Guanine (G) is a base. A always pairs with T in DNA.
C also pairs with G in DNA.
The amount of A is equal to the amoun tof T, same for C and G.
A+C=T+G
INTERESTING FACTS OF DNA
1. DNA was isolated in 1869 by Friedrich Miescher and its
Structure was figured out by James watson and Francis
Crick. It's a double helix.
2. The helix forms a ladder that twists to the right.
3. All cells in our body, but the red blood cells, have DNA.
4. Nuclear DNA (also known as chromosomal DNA) is found in
the nucleus of cells.
5. Humans have 46 chromosomes. Each chromosome can have
50 250 million base pairs.
6. Our entire DNA sequence is called a genome. Our genome has around 3 billion DNA
bases.
That would need 3 GB of storage space if we wanted to store each base in a computer.
7. If you unwrap all the DNA you have in all your cells, you could reach the moon 6000
times.
8. Over 99% of our DNA is the same as other humans
9. Genes are made of DNA. The average gene is 10.000 to 15.000 bases long.
Maxwell's Wheel

12. Principle
A disc, which can unroll with its axis on two cords, moves in the gravitational field.
Potential energy. Energy of translation and energy of rotation are converted into one
another and are determined as a function of time.
Tasks
The moment of inertia of the Maxwell disc is determined. Using the Maxwell disc,
1. The potential energy.
2. The energy of translation,
3. The energy of rotation,

13. NEWTON’S CRADLE
Objectives Students will:
• Build their own Newton’s Cradle
• Learn about the principal of conservation of momentum
Concepts The Newton’s Cradle is a desk toy named by one of the most important scientists,
Sir Isaac Newton. It demonstrates the scientific idea of momentum and the principal of
conservation of momentum in impacts (also called collisions) by moving one ball at the end
at a certain height and letting go to hit the other balls. Momentum can be defined as a
“mass in motion” and it measures the motion of an object. As an object with a certain mass
moves at greater velocities it has greater momentum or you can compare two objects of
different masses moving at the same velocity, the object that has greater mass will have a
greater momentum. For example, if Ball A has a mass of 10 lbs and Ball B has a mass of 20
lbs, and both balls are moving at 10 mph, Ball B will have a greater momentum than Ball A.
The equation for momentum is:
Momentum = Mass x Velocity
Now the principal of conservation of momentum is one of the most fundamental principals
in science and engineering. This principal states that the momentum in a collision must be
the same before the impact and after. In the case of the Newton’s Cradle each time the balls
on the ends strike the ones in the middle a force is transmitted through each ball until it
reaches the one on the opposite end that is free and it moves some distance. In an ideal
world the motion is never ending, since there are no external forces acting to reduce the
momentum. In our case in the real world the momentum decreases as each impact occurs,
this is due to energy being taken away by factors like friction, in the strings and the
interactions between each ball in the Newton’s Cradle. The basic equation for the principal
of conservation of momentum is:
mi x vi = mf x vf

14. JASTROW ILLUSION
The Jastrow illusion is an optical illusion discovered by the American psychologist
Joseph Jastrow in 1889. In this illustration, the two figures are identical, although the lower
one appears to be larger.
The illusion also occurs in the real world. The two toy railway tracks pictured are identical,
although the lower one appears to be larger. There are three competing theories on how
this illusion occurs.
This illusion is often included in magic kits and several versions are sold in magic shops
and is commonly known under the name Boomerang Illusion.
There are illusion puzzles that are related to the observer's frame of reference. Just as the
same in special theory of relativity, these illusions use the observer's frame of reference or
viewpoint. Below are two optical illusions. Try to answer the illusions and see in which
viewpoint can you see the solutions to these puzzles.
A. Which one is longer? A or B?

15. GEAR TRAIN
Gears are a variation of a wheel and axle in which the wheel has teeth along the
outside edge and works with another gear
 There are four basic purposes for using gears.
 To reverse the direction a gear or object is rotating.
 To change the speed of a rotating object.
 To change the position of a rotating axis.
 To keep two things in rotational motion synchronized.
Gears use teeth, the ridges along the circumference of the gear. The teeth prevent slipping
between the gears and allow for more precise gear ratios. By simply counting the teeth the
gear ratio can be determined. If the top gear has 30 teeth and the bottom gear has 15 teeth,
then the gear ratio is exactly 2:1. The teeth also allow for minor imperfections in the
diameter of the gear not to matter. It would be very difficult to make two gears that are
exactly some ratio of each other. Over many thousands of rotations even the smallest
imperfection would cause the ratio to be off. The teeth keep the ratio exactly perfect and
constant.
The driving gear or the primary gear is the gear that gets rotated by a hand or crank and
then the gear after that is called the follower gear.
Thus for the above compound gear train, the total gear ratio can be given by,
itotal = i(simple gear train, S1) × i(simple gear train, S2)
itotal = T2/T1 X T4/T3
Due to the different number of teeth, the compound gear helps to affect the total gear ratio
of the compound gear train.

16. PERCEIVING DEPTH
Abstract
Depth perception is the ability to see the three-dimensional volume of objects and the
spatial layout of objects relative to one another and the viewer. Humans accomplish depth
perception using a variety of cues, including some based on how the eyes and brain
function in concert and others that rely on lawful regularities in the environment. The topics
emphasized in this article are consistent with a current imbalance in scientific
understanding, which is that much more is known about the specific cues involved than
about how the brain uses these cues to achieve depth perception.
Depth Perception
Depth perception is the ability to distinguish distances between objects. One simple clinical
depth perception screening test, depicted in Figure, is to hold your index fingers pointing
upward in front of the patient at eye level, one finger closer to the patient than the other.
Gradually move the index fingers toward each other (one forward, one back) until the
patient identifies when the fingers are parallel or lined up. If the patient’s perception of
parallel is off by 3 inches or more, depth perception may be a problem and referral to an
ophthalmologist for additional investigation is warranted.
Look through the hole with one eye you see Fish game scene. You note that the illusion
which you look at it from sufficient distance. We can see an object from two different angles
with help of two eyes. These two different visions mix up is the brain and thus we have
perception of depth with one eye or from a large distance we naturally have only vision
from a certain angle and so we cannot perception of depth.

17. MINI ELECTRIC GENERATOR
Electricity is one form of energy that is produced due to flow of charge. We can use
electricity in many ways such as lights, electric vehicles, running electronic devices as
computer, television etc. Electricity can also be generated by different methods. Today we
are making “Electric Generator Model”
Electric generator helps us to understand about Dc motor. With some common items found
around our house like plywood, dc motor, copper wire, led, etc.
A generator is a machine that converts mechanical energy into electrical energy. It works
based on the principle of the faraday law of electromagnetic induction. The faradays law
states that whenever a conductor is placed in a varying magnetic field, EMF is induced and
this induced EMF is equal to the rate of change of flux linkages. This EMF can be generated
when there is either relative space or relative time variation between the conductor and the
magnetic field. So the important elements of a generator are:
 Magnetic field
 The motion of the conductor in a magnetic field

18. CENTRIFUGAL LOAD LIFTER
AIM: ‘’Centrifugal" weight spinning causing vertical weight to lift.
PROCCEDURE: Weight spinning causing vertical weight to lift
In the horizontal plane there is only one force acting on the rotation mass and that force is
the horizontal component of the tension on the string acting radially inwards.
The equation of motion of the mass on the need of the string is Thorizontal = mv2
/r
where m is the mass on the end of the string, v its speed and r the radius of the circle.
Now assume that Thorizontal stays approximately constant, ≈Mg, where M is the mass of the
hanging weight, what will happen if the speed of the rotating mass is increased?
Thorizontal, and m cannot change so the only way for the equation of motion to be satisfied is
for r to increase, Thorizontal = mv2
↑/r↑ to increase the radius the hanging mass must rise up.
The intermediate phase of the radius of motion of the rotating mass increasing and the
hanging mass accelerating upwards is complex. The hanging mass is subjected to a net
upward force and the rotating mass as well as rotating faster also has a net radial
acceleration with the radius of the motion increasing. Think of the following as infinitesimal
steps.
The rotating mass is made to move faster and to keep rotating mass at the same radius the
tension in the string must increase. An increase in the tension of the string will result on a
net force on the hanging mass and the hanging mass will move upwards. The radius of the
motion of the rotating mass increases so it needs a small tension to maintain its motion.
The net force on the hanging mass decreases such that the hanging mass is no longer
moving upwards.

19. DIP TUNNEL INFINITE MIRROR WALL
The infinity mirror (also sometimes called an infinite mirror) is a configuration of two
or more parallel or nearly parallel mirrors, creating a series of smaller and smaller
reflections that appear to recede to infinity. Often the front mirror of an infinity mirror is
half-silvered (a so-called one way mirror), but this is not required to produce the effect. A
similar appearance in artworks has been called the Droste effect. Infinity mirrors are
sometimes used as room accents or in works of art.
An infinity mirror creates an optical illusion of an infinitely long tunnel. It actually consists
of two mirrors — a regular mirror and a one-way mirror — with light emitting diodes (LEDs)
sandwiched between them. When the LEDs are turned off, the infinity mirror acts just like a
regular mirror. But when the LEDs are turned on, the infinity mirror looks like a brightly lit
tunnel that stretches off to infinity.
Materials and Equipment
 Mirror
 Plexiglass or acrylic sheet
 Mirrored window film
 Cardboard box or other container
 LEDs
 Power supply
 Tape or glue
 Cutting tool
 Safety glasses or protective goggles
The 3D illusion mirror effect is produced whenever there are two parallel reflective
surfaces which can bounce a beam of light back and forth an indefinite (theoretically
infinite) number of times. The reflections appear to recede into the distance because the
light actually is traversing the distance it appears to be traveling.

20. SEISMOGRAPHIC ALARM
Seismographs operate on the principle of inertia -- stationary objects, such as the
weight in the above picture; remain stationary unless a force is applied to them. The weight
thus tends to remain stationary while the frame and drum are moving.
A seismograph is a device for measuring the movement of the earth, and consists of a
ground-motion detection sensor, called a seismometer.
A seismograph aids scientists in detecting earthquakes and measuring several aspects of
the event, such as:
 The time at which the earthquake occurred.
 The epicenter is the location on the surface of the Earth below which the
Earthquake occurred.
 The depth below the Earth’s surface at which the earthquake occurred.
 The amount of energy released by the quake.
Seismometers used in earthquake studies are designed to be highly sensitive to
ground movements, so that movements as small as 1/10,000,000 centimetres (distances
almost as small as atomic spacing) can be detected at very quiet sites. The largest
earthquakes, such as the magnitude 9.1 Sumatra-Andaman Islands earthquake in 2004,
create ground motions over the entire Earth that can be several centimeters high.
Functioned with the relationship between seismic magnitude and acceleration, so that we
can resort to the software enquiry to figure out the seismic magnitude. In addition, large
variation on Z axis would trigger the alarm that earthquake is coming. The procedure has
been simulated and debugged on the actual Printed Circuit Board and a summary was
made.

21. REFLECTION OF LIGHT
When a ray of light approaches a smooth polished surface and the light ray bounces
back, it is called the reflection of light. The incident light ray that land on the surface is
reflected off the surface. The ray that bounces back is called the reflected ray.
1. A mirror in such a microscope is used to reflect light toward the specimen underneath
the microscope. To capture faint light from faraway stars, an astronomical reflecting
telescope employs a huge parabolic mirror.
2. To reflect the picture towards the eyepiece, a plane mirror is employed. As reflectors,
parabolic mirrors have been utilized in torches as well as automotive headlights.
Therefore, the light reflection would be the basic occurrence of light rebounding back
after striking an object.
For each type of reflection, each individual ray follows the law of reflection. However,
the roughness of the material means that each individual ray meets a surface which has a
different orientation. The normal line at the point of incidence is different for different rays.
Subsequently, when the individual rays reflect off the rough surface according to the law of
reflection, they scatter in different directions. The result is that the rays of light are incident
upon the surface in a concentrated bundle and are diffused upon reflection. The diagram
below depicts this principle. Five incident rays (labeled A, B, C, D, and E) approach a
surface. The normal line (approximated) at each point of incidence is shown in black and
labeled with an N. In each case, the law of reflection is followed, resulting in five reflected
rays (labeled A,, B,, C,, D,, and E,).

22. LEVER REDUCE EFFORT
If the fulcrum is closer to the load, then less effort is needed to move the load a
shorter distance. Observe that equal weights are placed at one end of lever while the
fulcrum is at the other end. Note the position of the handles. Pull the lever handles one by
one try to lift the weight. Note that it is easier to lift the weight when the handle is near to
the weight i.e. when the effort arm is longer. These kinds of levers are called levers of 3rd
order. your lower arm tweezer and sugar tone are all 3rd
order levers.
A lever is used to do some work with less effort that means a lever increases the
input force to give the more output force. Once again, the further away the effort force is
from the fulcrum and the output force or load the greater the advantage of the lever system.

23. PROJECTOR USING CONVEX LENS
This type of lens is widest at the centre and thinnest at the edges. The lens
converges rays of light travelling parallel to its principal axis. This results in the formation
of a focused image. The principal focus of the lens is the point in front of the lens where the
converged rays meet.
Working:
In this case, the camera was placed at a distance between F and 2F away from the lens. This
positioning results in a magnified, inverted and real image on the wall. The term ‘real’
means that the light rays converged in order to form the image. Since the lens inverts the
image on the phone’s screen, the image must be fed into the lense upside down. The fact
that the phone’s screen was brightly and evenly lit helps improve image quality.
Application:
 Projectors are an integral part of modern communication. They are used for home
cinema, in the education sector, for conferencing and throughout the entertainment
industry.
 Tech companies compete viciously to produce products capable of full HD and 4k
colour.
 Gaming projectors are adopting a similar concept. Projectors which are capable of
augmenting any surface to become a touchscreen are currently in the research
phase, but hold a lot of promise.

24. MAGNETIC LEVITAION
Magnetic levitation is a process in which an object can be suspended with no support
other than magnetic fields. Magnetic levitation is also known as magnetic suspension or
maglev.
Working :
Magnets have the property that their unlike poles react and like poles repel. The alignment
of two magnets depends on whether they attract or repel. This project makes us discover
how the two magnets create a repelling force between them. Later, we used that same
information to create our own magnetic levitation device.
Application:
Magnetic levitation is used in:
 Magnetic bearings
 Maglev trains
 Contactless melting

25. ANTI-GRAVITY DISC
Anti-gravity:
Anti-gravity (also known as non-gravitational field) is a hypothetical phenomenon of
creating a place or object that is free from the force of gravity. It does not refer to the lack of
weight under gravity experienced in free fall or orbit, or to balancing the force of gravity
with some other force, such as electromagnetism or aerodynamic lift. Anti-gravity is a
recurring concept in science fiction.
Application:
 Balancing the force of gravity.

26. WHICH ONE IS HEAVY
There are two boxes kept on the table. One is bigger and another is smaller first
lift the bigger box by the handle lower it down gently. Now lift the smaller box.
Which one is lighter? You will fill that smaller box heavier.
As you lift the bigger box its size and weight precondition your brain. This precondition
tends you to apply half effort to lift the smaller box. But in reality you would apply same
effort to lift the smaller box, hence to feel the difference.
Both are of the same weight as they weigh but, larger wooden box occupies more
space than smaller box i.e. volume of larger box is greater than that of smaller box. On
Earth smaller box would be heavier. Density of larger box is less than smaller box so it
would have more volume. So larger box will displace more air particles than smaller box.
FORMATION OF MULTIPLE IMAGES WITH PLANE MIRRORS

27. Now change the angle between the mirrors as given in the following table and count the
number of images each time. How is this number related to the measure of the angle?
Discuss this relationship.
a) The number of images formed when an object is placed between the two plane
mirrors at an angle of 90°, is 3 Three images are formed.
We know that two mirrors kept perpendicular to each other, produce three images for
an object that is placed in between them. i.e, the angle between two mirrors is 60°,
n=360°/90° = 4, number of images = n-1 = 4-1 = 3.
b) The number of images formed if an object is placed between two plane mirrors with
an angle of 60°, is five. Five images are formed: i.e, the angle between two mirrors is
60°, n=360°/60° = 6, number of images = n-1 = 6-1 = 5.

28. ILLUSION OF 2D TO 3D
Turn on the switch to rotate the shape. Observe what it turns into. The figure you observe is
illusionary and is formed due to persistence of vision. This phenomenon is used in motion
of shapes.
Principle:
An autostereogram is a two-dimensional (2D) image that can create the optical
illusion of a three-dimensional (3D) scene. To create 3D model of internal Geneva
mechanism using 2D shapes and perform motion analysis. It is a mechanism that translates
a continuous rotation movement into intermittent 3D shapes. 2D shapes having two axes
i.e. x-axis and y-axis. When we give it rotary motion, another axis is created i.e. z-axis. So as
a result, the 2D shape is converted into a 3D shape.

29. HOLOGRAM 3D MODEL
Hologram technology is a three-dimensional projection which can be seen without using
any special equipment such as cameras or glasses. The image can be viewed from any
angle, so as the user walks around the display the object will appear to move and shift
realistically. Holographic images can be static, such as a picture of a product, or they may
be animated sequences which can be watched by multiple people from any viewpoint.

30. CONDUCTIVITY TEST FOR LIQUID MATERIALS
 To observe electrical conductivity of substances in various aqueous solutions
 To determine of the solution is a strong or weak electrolyte
 To interpret a chemical reaction by observing aqueous solution conductivity.
Electrical conductivity is based on the flow of electrons. Metals are good conductors of
electricity because they allow electrons to flow through the entire piece of material. Thus,
electrons flow like a “sea of electrons” through metals. In comparison, distilled water is a
very poor conductor of electricity since very little electricity flows through water. Highly
ionized substances are strong electrolytes. Strong acids and salts are strong electrolytes
because they completely ionize (dissociate or separate) in solution. The ions carry the
electric charge through the solution thus creating an electric current. The current, if
sufficient enough, will light one or both LEDs on a conductivity meter, shown at right.
Place the meter so that the circuit board is facing up (the battery will be below). On this
side, there is a guide to the possible conductivity measurements:
Solutions LED Conductivity
Copper sulphate Very Bright Very high
Acetic acid Bright High
Simple water Medium Medium
Sugar water Dim low