the current topic contain information about anatomy of human eye and defect in vision and their corrections the p.p.t. also explain dispersion and scattering of light this p.p.t.is very useful f for secondary classes students
Class 10 Light Reflection and Refraction 1.ppsxAlphinJohnson3
Light Reflection and Refraction
This presentation has complete information about the NCERT Science Chapter 'Light - Reflection and Refraction'.
Don't forget to like if you likr it!!
Class 10 Light Reflection and Refraction 1.ppsxAlphinJohnson3
Light Reflection and Refraction
This presentation has complete information about the NCERT Science Chapter 'Light - Reflection and Refraction'.
Don't forget to like if you likr it!!
Convex lens uses functions and types.pdfChloe Cheney
The main purpose of the convex lens is to converge the light coming from an external source, and as a result, the light is focused on the other side of the lens
telescope
1. Telescopes
2. Telescopes represent an effective way of producing magnification without changing the working distance. Disadvantages They have a restricted field of view Often used to focus on objects closer than infinity Can be modified to correct for the Px’s refractive error.
3. There are two basic kinds of Telescope. Keplerian or Astronomical
4. Galilean Telescopes
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
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Light - Reflection and Refraction, Class X, CBSE, ScienceDevesh Saini
PowerPoint Presentation covering all the concepts and topics of the chapter : Light- Reflection and Refraction of class X (CBSE).
This is exactly what you are looking for.
Don't forget to comment and give feedback.
Physics ( human eye and the colourful world).Nikhil Dahiya
ppt on human eye and its structure. shows different parts of the eye . helps the student to learn about the eye more breifly.it is a science ppt which will be helpfull . teachers can also take it in the us for letting the students understand better .
Convex lens uses functions and types.pdfChloe Cheney
The main purpose of the convex lens is to converge the light coming from an external source, and as a result, the light is focused on the other side of the lens
telescope
1. Telescopes
2. Telescopes represent an effective way of producing magnification without changing the working distance. Disadvantages They have a restricted field of view Often used to focus on objects closer than infinity Can be modified to correct for the Px’s refractive error.
3. There are two basic kinds of Telescope. Keplerian or Astronomical
4. Galilean Telescopes
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.for more details please visit
www.indiandentalacademy.com
Light - Reflection and Refraction, Class X, CBSE, ScienceDevesh Saini
PowerPoint Presentation covering all the concepts and topics of the chapter : Light- Reflection and Refraction of class X (CBSE).
This is exactly what you are looking for.
Don't forget to comment and give feedback.
Physics ( human eye and the colourful world).Nikhil Dahiya
ppt on human eye and its structure. shows different parts of the eye . helps the student to learn about the eye more breifly.it is a science ppt which will be helpfull . teachers can also take it in the us for letting the students understand better .
In the realm of biology, the human eye is a marvel of nature's engineering, allowing us to perceive the world around us with clarity and detail. It is not only a sensory organ but also a gateway to understanding the physics of light and color. Class 10 Science introduces students to the intricacies of the human eye and its interaction with light, delving into topics such as refraction, dispersion, and the perception of color. In this detailed study guide, we will explore these concepts comprehensively to aid students in understanding this fascinating aspect of biology and physics.
For more information, visit-www.vavaclasses.com
The human eye is one of the most valuable and sensitive sense organs in the human body. It enables us to see the wonderful world and colours around us.
Structure of eye:
The human eye has the following main parts:
Cornea: It is the transparent spherical membrane covering the front of the eye. Light enters the eye through this membrane.
Crystalline lens: The eyes lens is a convex lens made of a transparent, soft and flexible material like a jelly made of proteins.
Iris: It is a dark muscular diaphragm between the cornea and the lens. It controls the size of the pupil. It is the colour of the iris that we call as the colour of the eye.
Pupil: It is a small hole between the iris through which light enters the eye. In dim light, it opens up completely due to expansion of iris muscles, but in bright light it becomes very small due to contraction of iris muscles.
The presentation explain principal, working and construction and application of Potentiometer it is useful for senior secondary students of Indian school
The presentation explain Wheatstone bride and its application for determination of current , resistances in network .The presentation also explain principle ,construction and working also application of meter bridge . it is useful foe students who are studying physics in senior secondary level in Indian school
the presentation explain about drift velocity ,motion of electrons under the influence of external electric field. resistivity and resistances of mater .how the resistivity varies with temperature
The following presentation explain about electric charge ,its properties and methods of charging a body .the presentation also explain electrostatic force
reflection of light by plane and spherical mirror use of spherical mirror and use of mirror formula .the presentation is very useful for class X students who studying physics
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
Normal Labour/ Stages of Labour/ Mechanism of LabourWasim Ak
Normal labor is also termed spontaneous labor, defined as the natural physiological process through which the fetus, placenta, and membranes are expelled from the uterus through the birth canal at term (37 to 42 weeks
Thinking of getting a dog? Be aware that breeds like Pit Bulls, Rottweilers, and German Shepherds can be loyal and dangerous. Proper training and socialization are crucial to preventing aggressive behaviors. Ensure safety by understanding their needs and always supervising interactions. Stay safe, and enjoy your furry friends!
This presentation includes basic of PCOS their pathology and treatment and also Ayurveda correlation of PCOS and Ayurvedic line of treatment mentioned in classics.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
How to Build a Module in Odoo 17 Using the Scaffold MethodCeline George
Odoo provides an option for creating a module by using a single line command. By using this command the user can make a whole structure of a module. It is very easy for a beginner to make a module. There is no need to make each file manually. This slide will show how to create a module using the scaffold method.
Safalta Digital marketing institute in Noida, provide complete applications that encompass a huge range of virtual advertising and marketing additives, which includes search engine optimization, virtual communication advertising, pay-per-click on marketing, content material advertising, internet analytics, and greater. These university courses are designed for students who possess a comprehensive understanding of virtual marketing strategies and attributes.Safalta Digital Marketing Institute in Noida is a first choice for young individuals or students who are looking to start their careers in the field of digital advertising. The institute gives specialized courses designed and certification.
for beginners, providing thorough training in areas such as SEO, digital communication marketing, and PPC training in Noida. After finishing the program, students receive the certifications recognised by top different universitie, setting a strong foundation for a successful career in digital marketing.
Delivering Micro-Credentials in Technical and Vocational Education and TrainingAG2 Design
Explore how micro-credentials are transforming Technical and Vocational Education and Training (TVET) with this comprehensive slide deck. Discover what micro-credentials are, their importance in TVET, the advantages they offer, and the insights from industry experts. Additionally, learn about the top software applications available for creating and managing micro-credentials. This presentation also includes valuable resources and a discussion on the future of these specialised certifications.
For more detailed information on delivering micro-credentials in TVET, visit this https://tvettrainer.com/delivering-micro-credentials-in-tvet/
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
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A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Executive Directors Chat Leveraging AI for Diversity, Equity, and InclusionTechSoup
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2. The students will be know the structure of
human eye.
The students will be understand defect in
vision and its remedy .
The students will be understand various
natural phenomenon related to optics
3. The students are know that light is form of
energy.
The students understand nature of light
waves .
The students are understand about reflection
and refraction of light .
4. Structure of human eye
Defect of vision in human eye
Refraction of light by glass prism
Dispersion of light by glass prism
Formation of rainbow
Atmospheric refraction
5.
6. The human eye is the sense organ which helps us to see the
colourful world around us.
The human eye is like a camera. Its lens system forms an image on
a light sensitive screen called retina. The eye ball is almost spherical
in shape with a diameter of about 2.3cm. Light enters the eye through a
transparent membrane called cornea. Behind the cornea is a muscular
diaphragm called iris which has an opening called pupil. The pupil
controls the amount of light entering the eye. The eye lens helps to
focus the image of objects on the retina. The ciliary muscles helps to
change the curvature of the lens and to change its focal length.
b) Working of the eye :-
The eye lens forms a real inverted image of the object on the
retina. The light sensitive cells in the retina then produce electrical
signals which are carried by the optic nerves to the brain. The brain
processes the information and sends the message to the eye and then
we see the object.
7. c) Power of accomodation of the eye :-
The ability of the eye lens to see both near and distant objects by
adjusting its focal length is called the power of accommodation of the
eye.
d) Near point :-
The minimum distance at which the eye can see objects clearly is
called the near point or least distance of distinct vision. For a normal
eye it is 25cm.
e) Far point :-
The farthest distance up to which the eye can see objects clearly is
called the far point of the eye. For a normal eye it is between 25cm and
infinity.
8. i) Myopia or near sightedness :-
Myopia is a defect of vision in which a person can see nearby
objects clearly but cannot see distant objects clearly because the
image is formed in front of the retina.
This may be due to:-
i) Increase in curvature of the eye lens
ii) Increase in the length of the eye ball
It can be corrected by using suitable concave lens.
Myopic eye
Correction using concave lens
9. Hypermetropia is a defect of vision in which a person can see
distant objects clearly but cannot see nearby objects clearly because
the image is formed behind the retina.
This may be due to:-
i) Decrease in curvature of eye lens
ii) Decrease in the length of the eye ball
It can be corrected by using a suitable convex lens.
Hypermetropic eye
Correction using convex lens
10. Presbyopia is a defect of vision in old people in
which they are not able to see nearby objects clearly due
to the increase in the distance of near point.
This is due to the weakening of the ciliary muscles
and decrease in the flexibility of the eye lens. It can be
corrected by using suitable convex lens.
Sometimes they are not able to see both nearby and
distant objects clearly. It can be corrected by using
bifocal lenses consisting of both concave and convex
lenses. The upper part is concave for correction of
distant vision and the lower part is convex for correction
of near vision.
11. When a ray of light passes through a glass prism, it gets
bent twice at the air- glass interface and glass- air interface.
The emergent ray is deviated by an angle to the incident
ray.This angle is called the angle of deviation.
Incident ray
Refracted ray
Emergent ray
D
i
r
Air Glass Glass Air
Glass prism
e Angle of emergence
Angle of deviation
Normal
12. When a beam of white light is passed through a glass
prism, it is split up into a band of colors called spectrum.
This is called dispersion of white light. The spectrum of
white has the colors violet, indigo, blue, green, yellow,
orange and red (VIBGYOR). The red light bends the least and
the violet light bends the most.
Beam of white light
Spectrum
R
O
Y
G
I
B
V
Glass prism
13. When a beam of white light is passed through a glass
prism, it is split up into its component colours. When these
colours are allowed to fall on an inverted glass prism it
recombines to produce white light.
R
V
V
R R
VWhite light
White light
Glass prisms
14. A rainbow is a natural spectrum appearing in the sky after
a rain shower. It is caused by the dispersion of sunlight by
water droplets present in the atmosphere. The water droplets
act like small prisms. They refract and disperse the sunlight
then reflect it internally and finally refract it again when it
comes out of the rain drops. Due to the dispersion of sunlight
and internal reflection by the water droplets we see the
rainbow colours.
Sunlight
Raindrop
Red Violet
Refraction and dispersion
Internal reflection
Observer
Refraction
15. Atmospheric refraction is due to the gradual change in the
refractive index of the atmosphere. The refractive index of the
atmosphere gradually increases towards the surface of the
earth because the hot air above is less dense than the cool air
below. So light gradually bends towards the normal. So the
real position of a star is different from its apparent position.
Apparent position
Real position
Eye
Star
Increasing
refractive index
of atmosphere
16.
17.
18. Earth
Observer
SunriseSunset
Apparent positionApparent position
Atmosphere
The sun is visible to us about 2 minutes before sunrise
and about two minutes after sunset due to atmospheric
refraction.
The apparent flattening of the sun’s disc at sunrise and at
sunset is also due to atmospheric refraction.
Horizon Horizon
Real position Real position
19. i) Tyndall effect :-
When a beam of light passes through a colloidal solution, the path of
light becomes visible due to the scattering of light by the colloid particles.
This is known as Tyndall effect.
The earth’s atmosphere contains air molecules, water droplets, dust,
smoke etc. When sunlight passes through the atmosphere the path of the
light becomes visible due to the scattering of light by these particles.
The colour of the scattered light depends upon the size of the scattering
particles. Very fine particles scatter blue light. Larger particles scatter
different colours of light.
20.
21. The fine particles in the atmosphere have size smaller than
the wave length of visible light. They can scatter blue light
which has a shorter wave length than red light which has a
longer wave length. When sunlight passes through the
atmosphere, the fine particles in the atmosphere scatter the
blue colour more strongly than the red and so the sky appears
blue.
If the earth had no atmosphere there would not be any
scattering of light and the sky would appear dark. The sky
appears dark at very high altitudes.
22.
23. At sunrise and at sunset the sun is near the horizon and the
light from the sun travels through the thicker layers of the
atmosphere and longer distance through the atmosphere. Near
the horizon most of the blue light and shorter wave lengths are
scattered away by the particles of the air and the red light and
longer wave lengths reaches our eyes. So the sun appears
reddish at sunrise and sunset.
Observer
Sun near horizon
Sun overhead
Blue light scattered away
Sun appears reddish
Atmosphere
Earth
24. The ability of the eye to focus both near and distant objects, by adjusting its focal
length, is called the accommodation of the eye.
The smallest distance, at which the eye can see objects clearly without strain, is
called the near point of the eye or the least distance of distinct vision. For a young
adult with normal vision, it is about 25 cm.
The common refractive defects of vision include myopia, hypermetropia and
presbyopia. Myopia (short-sightedness – the image of distant objects is focussed
before the retina) is corrected by using a concave lens of suitable power.
Hypermetropia (far-sightedness – the image of nearby objects is focussed beyond
the retina) is corrected by using a convex lens of suitable power. The eye loses its
power of accommodation at old age. The splitting of white light into its component colours is
called dispersion.
Scattering of light causes the blue colour of sky and the reddening of the Sun at
sunrise and sunset
25. 1. The human eye can focus objects at different
distances by adjusting the focal length of the eye lens.
This is due to
(a) presbyopia.(b) accommodation.(c) near-sightedness.
(d) far-sightedness
2. The human eye forms the image of an object at its
(a) cornea. (b) iris. (c) pupil. (d) retina.
3. The least distance of distinct vision for a young adult
with normal vision is about
(a) 25 m. (b) 2.5 cm. (c) 25 cm. (d) 2.5 m.
4. The change in focal length of an eye lens is caused by
the action of the
(a) pupil. (b) retina. (c) ciliary muscles. (d) iris.
26. 1. A person needs a lens of power –5.5 dioptres for correcting his distant vision. For
correcting his near vision he needs a lens of power +1.5 dioptre. What is the focal
length of the lens required for correcting (i) distant vision, and (ii) near vision?
2. The far point of a myopic person is 80 cm in front of the eye. What is the nature and
power of the lens required to correct the problem?
3 Make a diagram to show how hypermetropia is corrected. The near point of a
hypermetropic eye is 1 m. What is the power of the lens required to correct this
defect? Assume that the near point of the normal eye is 25 cm.
4. Why is a normal eye not able to see clearly the objects placed closer than
25 cm?
5. What happens to the image distance in the eye when we increase the distance of an
object from the eye?
6. Why do stars twinkle?
7. Explain why the planets do not twinkle.
8 Why does the Sun appear reddish early in the morning?
9 Why does the sky appear dark instead of blue to an astronaut?