Table of Contents
Light – Worksheets
Hello Students,
Welcome to your set of worksheets on the chapter “Light.” This chapter is an integral part of your science curriculum, introducing you to the fundamental concepts of light, its properties, and how it behaves. These concepts are not only fascinating but also crucial for understanding the principles of optics and physics.
In this chapter, you have explored-
- Nature of Light- Understanding that light travels in straight lines and how this principle is observed in our daily life.
- Reflection of Light- Learning about how light reflects off surfaces like mirrors and the laws governing reflection.
- Types of Mirrors and Reflection- Exploring different types of mirrors (plane, concave, and convex) and how they affect the reflection of light.
- Formation of Images by Mirrors- Understanding how images are formed in different types of mirrors and their characteristics.
- Lenses and Image Formation- Studying how lenses bend light and the types of images formed by convex and concave lenses.
- Dispersion of Light- Exploring how white light can be dispersed into its constituent colours, forming a spectrum.
The worksheets include a variety of questions that will help you revise and deepen your understanding of these topics. These exercises are designed to test your knowledge, stimulate your curiosity, and prepare you for your exams. By completing these worksheets, you will enhance your grasp of the fascinating world of light and its properties.
Also Check – Class 7 Science -Chapter 15 – Light- Complete Notes
Worksheet 1 – Chapter 11 – Light – Student Worksheet (Unsolved)
Conceptual Understanding-
(a) Define light and explain its role in visual perception.
(b) How does the straight-line movement of light demonstrate through the experiment with pipes?
Interactions of Light–
(a) Distinguish between transparent, translucent, and opaque objects with examples.
(b) How does the nature of a surface affect the reflection of light?
True or False – Justify Your Answer-
(a) Light can bend around corners. (T/F)
(b) A concave mirror always forms a real image. (T/F)
Multiple Choice Questions-
(a) What causes the dispersion of light?
(i) Reflection
(ii) Refraction
(iii) Diffraction
(iv) Absorption
(b) What type of image is formed by a plane mirror?
(i) Real and inverted
(ii) Virtual and erect
(iii) Real and erect
(iv) Virtual and inverted
Practical Application-
Describe the process of dispersion of light through a prism and its significance in understanding the nature of light.
Fill in the Blanks-
(a) In the formation of rainbows, light undergoes __________ and __________ within raindrops.
(b) Lateral inversion is a phenomenon observed in __________ mirrors.
Analysing Spherical Mirrors-
Compare and contrast the image characteristics in concave and convex mirrors.
Scenario-Based Question-
If you observe a candle through a bent pipe and cannot see it, what does it tell you about the nature of light?
Discussion-Based Questions
Discuss how the laws of reflection are applicable in everyday life, especially in the design of various optical devices.
Diagram-Based Question-
Draw a ray diagram to show the formation of an image by a plane mirror.
Also Check – NCERT Solutions for Class 7 Science Chapter 15 -Light
Worksheet 1 – Chapter 11 – Light – Solved Worksheet with Answer
Conceptual Understanding-
(a) Definition of Light and Its Role in Visual Perception-
Light is a form of energy that is visible to the human eye and is essential for sight. It enables visual perception by illuminating objects, which then reflect light into our eyes. This light is processed by the eye and brain to create the images we see.
(b) Straight-line Movement of Light-
The straight-line movement of light can be demonstrated using a pipe experiment. When light is shone through a series of straight, aligned pipes, it passes through to the other end. However, if the pipes are bent or not aligned, the light cannot pass through, demonstrating that light travels in straight lines.
Interactions of Light-
(a) Distinguishing between Transparent, Translucent, and Opaque-
Transparent objects (e.g., clear glass) allow light to pass through them clearly. Translucent objects (e.g., frosted glass) allow light to pass through but scatter it, making objects on the other side appear blurred. Opaque objects (e.g., wood) do not allow light to pass through them, creating a shadow.
(b) Effect of Surface Nature on Light Reflection-
The nature of a surface affects how light is reflected. Smooth, shiny surfaces (like mirrors) reflect light in a predictable direction. Rough surfaces scatter light in many directions, leading to diffuse reflection.
True or False – Justify Your Answer-
(a) Light can bend around corners. (F) – Light travels in straight lines and cannot bend around corners. This property is why shadows are formed and why light doesn’t turn corners.
(b) A concave mirror always forms a real image. (F) – Concave mirrors can form both real and virtual images, depending on the position of the object relative to the mirror.
Multiple Choice Questions-
(a) Cause of Dispersion of Light-
Answer- (ii) Refraction – Dispersion occurs when different wavelengths of light bend by different amounts upon passing through a medium, like a prism.
(b) Type of Image Formed by a Plane Mirror-
Answer- (ii) Virtual and erect – A plane mirror forms a virtual image that is erect and of the same size as the object.
Practical Application-
Dispersion through a Prism-
Dispersion through a prism occurs when white light passes through the prism and is refracted, or bent. The different wavelengths (colours) of light bend at slightly different angles due to their different speeds in the glass. This separation of light into its component colours demonstrates that white light is a mixture of different colours.
Fill in the Blanks-
(a) In the formation of rainbows, light undergoes refraction and reflection within raindrops.
(b) Lateral inversion is a phenomenon observed in plane mirrors.
Analysing Spherical Mirrors-
Comparison of Concave and Convex Mirrors-
Concave mirrors can produce real, inverted images if the object is beyond the focal point and virtual, erect images if the object is between the mirror and the focal point. Convex mirrors always produce virtual, erect, and diminished images, useful for viewing a wide area.
Scenario-Based Question-
Observation Through a Bent Pipe-
Observing a candle through a bent pipe and not seeing it confirms that light travels in straight lines. Since the pipe is bent, the light from the candle cannot follow the curved path, hence the candle is not visible.
Discussion-Based Questions
Application of the Laws of Reflection-
The laws of reflection are fundamental in designing optical devices like mirrors, periscopes, and telescopes. They are also crucial in everyday life, such as in the design of car mirrors, allowing drivers to see the road behind them.
Diagram-Based Question–
Image Formation by a Plane Mirror-
Draw a plane mirror with a line perpendicular to its surface, representing the normal. Draw an object in front of the mirror and two rays emanating from the top of the object- one hitting the mirror at 90 degrees and reflecting back on itself, and another hitting at an angle and reflecting according to the angle of incidence equaling the angle of reflection. The reflected rays should be extended backward to meet at a point behind the mirror, forming a virtual image that is erect and of the same size as the object.
Also Check – Convex Lenses- Principles, Applications, and Insights
Worksheet 2 – Chapter 11 – Light – Student Worksheet (Unsolved)
Describe and Differentiate-
(a) Explain the difference between diffused (irregular) reflection and regular reflection.
(b) Describe the characteristics of a real image and a virtual image.
The Behavior of Light-
(a) How does the texture of a surface affect the reflection of light?
(b) What is lateral inversion, and where is it commonly observed?
True or False – Provide Justification-
(a) Concave mirrors can only form virtual images. (T/F)
(b) Convex lenses are used in peepholes because they provide a wider field of view. (T/F)
Multiple Choice Questions-
(a) What happens to light when it passes through a prism?
(i) It is absorbed
(ii) It is totally reflected
(iii) It is dispersed into its component colours
(iv) It remains unchanged
(b) The image formed by a plane mirror is-
(i) Virtual and the same size as the object
(ii) Real and smaller than the object
(iii) Real and the same size as the object
(iv) Virtual and larger than the object
Application in Daily Life-
Discuss the practical uses of concave and convex mirrors in everyday life.
Fill in the Blanks-
(a) The angle between the incident ray and the normal is known as the __________.
(b) In rainbows, the dispersion of light occurs due to __________ of light.
Spherical Mirrors and Lenses-
Compare the uses and image formation in concave and convex lenses.
Scenario-Based Question-
If a person is standing in front of a concave mirror, how will their image appear as they move closer to and further from the mirror?
Discussion-Based Questions
Discuss how the understanding of the properties of light has led to advancements in optical technology.
Creative Thinking-
Design an experiment to demonstrate the principle of light travelling in a straight line.
Also Check – Difference Between a Convex and Concave Lens
Worksheet 2 – Chapter 11 – Light – Solved Worksheet with Answer
Describe and Differentiate-
(a) Diffused vs. Regular Reflection-
Diffused reflection occurs when light is reflected in many different directions due to an uneven or rough surface. Regular reflection happens on smooth, polished surfaces where parallel light rays are reflected in specific directions, maintaining their parallelism.
(b) Real vs. Virtual Images-
A real image is formed when light rays actually converge at a point, typically seen on a screen, and is inverted. A virtual image appears to form behind the mirror, cannot be projected on a screen, and is upright.
The Behavior of Light-
(a) Texture Effect on Light Reflection-
The texture of a surface greatly affects how light is reflected. Smooth surfaces reflect light in a predictable manner (regular reflection), while rough surfaces scatter light in multiple directions (diffused reflection).
(b) Lateral Inversion-
Lateral inversion is the phenomenon where an image appears reversed from left to right. It’s commonly observed in plane mirrors.
True or False – Provide Justification-
(a) Concave mirrors can only form virtual images. (F) – Concave mirrors can form both real and virtual images depending on the distance of the object from the mirror.
(b) Convex lenses are used in peepholes because they provide a wider field of view. (T) – Convex lenses are suitable for peepholes due to their ability to diverge light rays, allowing a broader view.
Multiple Choice Questions-
(a) Effect of Light Passing Through a Prism-
Answer- (iii) It is dispersed into its component colours – A prism disperses white light into its constituent spectrum of colours.
(b) Image Formed by a Plane Mirror-
Answer- (i) Virtual and the same size as the object – A plane mirror forms a virtual image that is upright and of the same size as the object.
Application in Daily Life-
Uses of Concave and Convex Mirrors-
Concave mirrors are used in applications like shaving or makeup mirrors, reflecting telescopes, and vehicle headlight reflectors, as they can magnify images or focus light. Convex mirrors are used as rear view mirrors in vehicles to give a wider field of view, in security mirrors in stores, and in street junctions for broader visibility.
Fill in the Blanks-
(a) The angle between the incident ray and the normal is known as the angle of incidence.
(b) In rainbows, the dispersion of light occurs due to refraction of light.
Spherical Mirrors and Lenses-
Comparison of Concave and Convex Lenses-
Concave lenses diverge light rays and are used in devices where spreading out light or reducing image size is needed, like in peepholes or glasses for myopia. Convex lenses converge light rays and are used to magnify images or focus light, such as in magnifying glasses, cameras, and glasses for hyperopia.
Scenario-Based Question-
Image in a Concave Mirror-
When a person stands far from a concave mirror, their image appears smaller and inverted. As they move closer to the mirror, the image becomes larger and remains inverted until they reach the focal point. Between the focal point and the mirror, the image becomes upright and magnified.
Discussion-Based Questions
Advancements in Optical Technology-
Understanding the properties of light has led to significant advancements in optical technology, including the development of various types of lenses and mirrors, sophisticated telescopes, microscopes, fibre-optic communication, and laser technology.
Creative Thinking-
Experiment to Demonstrate Straight-line Travel of Light-
Set up three cardboard pieces with a small hole in the centre of each, aligned in a straight line. Shine a flashlight through the holes. The light will only pass through all holes if they are perfectly aligned, demonstrating that light travels in a straight line.
Also Check – Chapter 11- A Detailed Guide to the Light Activities for Class 7 Students
Worksheet 3 – Chapter 11 – Light – Student Worksheet (Unsolved)
Conceptual Understanding-
(a) Define and explain the phenomenon of reflection of light.
(b) How does the nature of a surface (smooth vs. rough) affect the type of reflection (regular vs. diffused)?
Image Formation-
(a) Describe the characteristics of the image formed by a plane mirror.
(b) How does the distance between an object and a mirror affect the image formed?
True or False – Justify Your Answer-
(a) A convex mirror always forms a real image. (T/F)
(b) The image formed by a plane mirror undergoes left-right inversion. (T/F)
Multiple Choice Questions-
(a) What types of images can be formed by a concave mirror?
(i) Only real
(ii) Only virtual
(iii) Both real and virtual
(iv) Neither real nor virtual
(b) What is the role of a prism in the dispersion of light?
(i) It absorbs light
(ii) It refracts light, causing dispersion
(iii) It reflects light
(iv) It does not affect light
Practical Application-
Discuss the principle behind the formation of a rainbow and its relation to light refraction and reflection.
Fill in the Blanks-
(a) When light rays hit a smooth surface, they reflect at an equal __________ but opposite direction.
(b) __________ mirrors are used in vehicles’ rear-view mirrors for a wider field of view.
Analysing Spherical Mirrors-
Explain the differences in image formation between concave and convex mirrors, citing practical examples.
Scenario-Based Question-
If an object is placed between the focal point and a concave mirror, describe the nature of the image formed.
Discussion-Based Questions
Discuss the importance of understanding light properties in the design of optical instruments like telescopes and microscopes.
Creative Thinking-
Design an experiment to demonstrate the law of reflection using easily available materials.
Also Check – What is Light Reflection? A Simple Guide to Understanding Reflections
Worksheet 3 – Chapter 11 – Light – Solved Worksheet with Answer
Conceptual Understanding-
(a) Reflection of Light-
Reflection of light is the phenomenon where light rays bounce off a surface rather than being absorbed. This process changes the direction of the light ray. Regular reflection occurs on smooth surfaces like mirrors, where light is reflected in a predictable manner. Diffuse reflection happens on rough surfaces, scattering light in many directions.
(b) Effect of Surface Nature on Reflection-
Smooth surfaces cause regular reflection, where parallel light rays remain parallel after reflection. Rough surfaces cause diffuse reflection, where light rays are scattered in various directions, leading to a non-sharp image or none at all.
Image Formation-
(a) Characteristics of Image Formed by Plane Mirror-
The image formed by a plane mirror is virtual (cannot be projected on a screen), erect (upright), and of the same size as the object. The image is as far behind the mirror as the object is in front of it.
(b) Effect of Distance on Image Formation-
Changing the distance between the object and a plane mirror does not affect the size or type of the image; however, it affects the perceived distance of the image from the mirror.
True or False – Justify Your Answer-
(a) A convex mirror always forms a real image. (F) – Convex mirrors always form virtual, erect, and diminished images regardless of the object’s distance from the mirror.
(b) The image formed by a plane mirror undergoes left-right inversion. (T) – In plane mirrors, images undergo lateral inversion, meaning the left side of the object appears on the right side of the image and vice versa.
Multiple Choice Questions-
(a) Cause of Light Dispersion-
Answer- (iii) It is dispersed into its component colours – Dispersion of light occurs due to its refraction in mediums like a prism, separating it into a spectrum of colours.
(b) Image by Plane Mirror-
Answer- (ii) Virtual and erect – The image formed by a plane mirror is virtual, erect, and of the same size as the object.
Practical Application-
Principle Behind Rainbow Formation-
Rainbows are formed due to the dispersion, refraction, and total internal reflection of sunlight within raindrops. Sunlight is refracted as it enters a raindrop, disperses into a spectrum, reflects internally, and then refracts again as it exits the drop, forming a rainbow.
Fill in the Blanks-
(a) When light rays hit a smooth surface, they reflect at an equal angle but in the opposite direction.
(b) Convex mirrors are used in vehicles’ rear-view mirrors for a wider field of view.
Analysing Spherical Mirrors-
Differences in Image Formation-
Concave mirrors can form real or virtual images. A real image is formed when the object is beyond the focal point, and it’s inverted. A virtual image is erect and magnified, formed when the object is between the mirror and the focal point. Convex mirrors always form virtual, erect, and diminished images.
Scenario-Based Question-
Image Formed by Concave Mirror-
When an object is placed between the focal point and a concave mirror, the mirror forms a virtual, erect, and magnified image of the object.
Discussion-Based Questions
Importance of Understanding Light in Optical Instruments-
Understanding the properties of light is crucial for designing optical instruments like telescopes and microscopes. Knowledge about reflection, refraction, and image formation helps in optimising these instruments for clearer, more precise images, enabling detailed observations of distant celestial bodies or tiny biological specimens.
Creative Thinking-
Experiment to Demonstrate Reflection-
Set up a laser or flashlight, a mirror, and a protractor. Shine the light at a specific angle on the mirror and measure the angle of reflection. This experiment will demonstrate that the angle of incidence equals the angle of reflection, adhering to the law of reflection.
Also Check – What is Light? An Easy-to-Understand Guide
Worksheet 4 – Chapter 11 – Light – Student Worksheet (Unsolved)
Understanding Light-
(a) Explain the principle of rectilinear propagation of light.
(b) Describe the phenomenon and significance of dispersion of light.
Mirrors and Reflection-
(a) Distinguish between the images formed by concave and convex mirrors.
(b) Explain the concept of lateral inversion as observed in plane mirrors.
True or False – Justify Your Answer-
(a) Concave lenses are commonly used in magnifying glasses. (T/F)
(b) Sunlight is a mixture of seven different colours. (T/F)
Multiple Choice Questions-
(a) Which colour in the visible spectrum has the shortest wavelength?
(i) Red
(ii) Green
(iii) Blue
(iv) Violet
(b) What is the nature of the image formed by a convex lens when the object is placed very close to the lens?
(i) Real and inverted
(ii) Virtual and erect
(iii) Real and erect
(iv) Virtual and inverted
Practical Application-
Explain the concept of the formation of a rainbow in the sky, using the principles of refraction, dispersion, and total internal reflection.
Fill in the Blanks-
(a) __________ occurs when light rays change direction as they pass from one medium to another.
(b) A __________ mirror is used in vehicles to allow the driver to see a wider area.
Exploring Lenses-
Describe the differences in the functioning of convex and concave lenses, and provide examples of their practical applications.
Scenario-Based Question-
If an object is placed at the focus of a concave mirror, what kind of image would you expect to be formed?
Discussion-Based Questions
Discuss how the principles of light are applied in the design and function of optical instruments like cameras and telescopes.
Also Check – NCERT Exemplar Solutions- Class 7 Science- Chapter 15- Light
Worksheet 4 – Chapter 11 – Light – Solved Worksheet with Answer
Understanding Light-
(a) Rectilinear Propagation of Light-
Light always travels in a straight line. This rectilinear propagation of light can be observed when a beam of sunlight enters a room through a narrow opening, or the light beams from car headlights are visible as straight lines in foggy conditions.
(b) Dispersion of Light-
Dispersion of light occurs when white light is split into its component colours (red, orange, yellow, green, blue, indigo, violet) as it passes through a prism. This phenomenon demonstrates that white light is a mixture of different colours and is significant in explaining natural phenomena like rainbows.
Mirrors and Reflection-
(a) Images by Concave and Convex Mirrors-
Concave mirrors can form real, inverted images when the object is beyond the focal point and virtual, erect, and magnified images when the object is within the focal point. Convex mirrors always form virtual, erect, and diminished images regardless of the object’s distance.
(b) Concept of Lateral Inversion-
Lateral inversion is the phenomenon where the left and right sides of an image are reversed in a plane mirror. For example, if you raise your right hand, your mirror image appears to raise its left hand.
True or False – Justify Your Answer-
(a) Concave lenses are commonly used in magnifying glasses. (F) – Magnifying glasses typically use convex lenses because they can converge light and magnify images.
(b) Sunlight is a mixture of seven different colours. (T) – Sunlight, or white light, comprises seven colours, which can be seen when sunlight passes through a prism, forming a spectrum.
Multiple Choice Questions-
(a) Shortest Wavelength in the Visible Spectrum-
Answer- (iv) Violet – Violet has the shortest wavelength in the visible spectrum.
(b) Nature of Image by Convex Lens with Close Object-
Answer- (ii) Virtual and erect – When an object is very close to a convex lens, it forms a virtual and erect image.
Practical Application-
Formation of a Rainbow-
Rainbows are formed by the dispersion of sunlight by water droplets in the atmosphere. Sunlight enters a raindrop, refracts and disperses into its component colours, reflects off the inside surface of the droplet, and refracts again as it exits the drop. This process results in the formation of a colourful arc in the sky known as a rainbow.
Fill in the Blanks-
(a) Refraction occurs when light rays change direction as they pass from one medium to another.
(b) A convex mirror is used in vehicles to allow the driver to see a wider area.
Exploring Lenses-
Differences Between Convex and Concave Lenses-
Convex lenses are thicker in the middle and converge light rays, forming real or virtual images depending on the object’s position. They are used in magnifying glasses and cameras. Concave lenses are thinner in the middle and diverge light rays, forming virtual, erect, and diminished images. They are used in peepholes and glasses for myopia.
Scenario-Based Question-
Image by Concave Mirror at Focus-
If an object is placed at the focus of a concave mirror, the light rays reflected from the mirror become parallel and form an image at infinity. Hence, the image cannot be seen on a screen placed behind the mirror.
Discussion-Based Questions
Application of Light Principles in Optical Instruments-
The principles of light, such as reflection, refraction, and dispersion, are crucial in designing optical instruments like cameras, which use lenses to focus light and form images, and telescopes, which use mirrors or lenses to gather light from distant objects for detailed observation.
Also Check – Class 7 Science -Chapter 15- Light- Definition and Explanation of Important Keywords
Worksheet 5 – Chapter 11 – Light – Student Worksheet (Unsolved)
Fundamental Concepts-
(a) What is the principle behind the dispersion of light? Give an example where this phenomenon is observed in nature.
(b) Explain the rectilinear propagation of light with the help of an everyday observation.
Mirrors and Images-
(a) Compare the images formed by concave mirrors and convex mirrors in terms of position, size, and nature.
(b) Discuss the principle of lateral inversion with an example from daily life.
Analytical Questions-
(a) Describe the formation of a rainbow in the sky, incorporating the concepts of reflection, refraction, and dispersion.
(b) How does the size and nature of an image change when an object moves closer to a concave mirror?
True or False – Provide Explanation-
(a) The image formed by a plane mirror is always virtual and laterally inverted. (T/F)
(b) A convex lens can only form a diminished image of an object. (T/F)
Practical Applications-
(a) Explain how convex mirrors are used in vehicles and why.
(b) Describe the use of concave and convex lenses in spectacles to correct vision.
Fill in the Blanks-
(a) __________ is a phenomenon where light spreads out after passing through a small opening.
(b) The focus of a concave mirror is a point where light rays __________.
Diagram-Based Question-
Draw and label a ray diagram showing the image formation by a convex lens when the object is placed at twice the focal length.
In-depth Analysis-
Analyse how the change in the medium (air to water) affects the path of light rays. Discuss with examples.
Creative Thinking-
Design an experiment to demonstrate the principle of refraction using simple materials.
Also Check – Concave Lenses- Applications, Image Formation, and Principles
Worksheet 5 – Chapter 11 – Light – Solved Worksheet with Answer
Fundamental Concepts-
(a) Principle Behind Dispersion of Light-
Dispersion of light refers to the splitting of white light into its constituent colours (red, orange, yellow, green, blue, indigo, violet) when passing through a medium like a glass prism. This phenomenon occurs because different colours of light bend by different amounts due to their varying wavelengths. It is observed in nature as a rainbow.
(b) Rectilinear Propagation of Light-
The principle of rectilinear propagation states that light travels in straight lines. This can be observed when sunlight enters a room through a narrow slit or when a beam of light from a torch is visible in a foggy environment.
Mirrors and Images-
(a) Concave vs. Convex Mirrors-
Concave mirrors can form real, inverted images if the object is beyond the focal point, and virtual, erect, magnified images if the object is within the focal point. Convex mirrors always produce virtual, erect, and diminished images, regardless of the object’s distance.
(b) Principle of Lateral Inversion-
Lateral inversion is the phenomenon where an image appears horizontally flipped in a plane mirror. For instance, if you raise your right hand, your mirror image appears to raise its left hand.
Analytical Questions-
(a) Formation of a Rainbow-
A rainbow forms due to the dispersion, refraction, and total internal reflection of sunlight within raindrops. The sunlight is refracted as it enters a raindrop, disperses into its component colours, reflects internally at the back of the droplet, and refracts again as it exits, forming a rainbow.
(b) Image Change Near a Concave Mirror-
As an object moves closer to a concave mirror, the image size increases and becomes more magnified. When the object is very close to the mirror, the image becomes virtual, erect, and magnified.
True or False – Provide Explanation-
(a) The image formed by a plane mirror is always virtual and laterally inverted. (T) – The image in a plane mirror is virtual and undergoes lateral inversion, where left appears as right and vice versa.
(b) A convex lens can only form a diminished image of an object. (F) – A convex lens can form both diminished and magnified images, depending on the object’s distance from the lens.
Practical Applications-
(a) Use of Convex Mirrors in Vehicles-
Convex mirrors are used in vehicles as they provide a wider field of view, allowing drivers to see a larger area and make safer driving decisions.
(b) Spectacles with Concave and Convex Lenses-
Concave lenses are used in spectacles to correct myopia (short-sightedness) by diverging light rays, while convex lenses are used to correct hyperopia (long-sightedness) by converging light rays.
Fill in the Blanks-
(a) Diffraction is a phenomenon where light spreads out after passing through a small opening.
(b) The focus of a concave mirror is a point where light rays converge.
Diagram-Based Question-
Ray Diagram for Convex Lens-
Draw a convex lens with its principal axis. Place an object at twice the focal length from the lens. Draw two rays- one parallel to the principal axis, refracting through the lens and passing through the focal point on the other side, and another passing through the centre of the lens without deviation. The point where the two rays converge on the other side of the lens is where the image is formed, real, inverted, and of the same size as the object.
In-depth Analysis-
Change in Medium Affecting Light Path-
When light moves from air to water, its speed decreases, causing the light to bend or refract. This can be observed when a stick partially submerged in water appears bent at the water surface.
Creative Thinking-
Experiment to Demonstrate Refraction-
Place a pencil in a half-filled glass of water. Observe the pencil from the side of the glass. The pencil will appear bent at the water surface due to refraction, demonstrating how light changes direction when moving between different mediums.
Also Check- Chapter 15- Light Class 7 science- Question and Answer (Fill in the Blanks)
Also Check – Chapter 15- Light Class 7 science- Question and Answer (True or False)
Also Check – Chapter 15- Light Class 7 science- Extra Question and Answers
