--- type: "Chapter" knowledge_type: "chapter" entity_type: "chapter" id: "69bff571fb5daab696da613b" title: "Light: Shadows and Reflections" board: "CBSE" curriculum: "CBSE" class: "Class 7" subject: "Science" book: "Curiosity" chapter: "Light: Shadows and Reflections" chapter_slug: "light-shadows-and-reflections" canonical_url: "https://www.edzy.ai/cbse-class-7-science-curiosity-light-shadows-and-reflections" markdown_url: "https://www.edzy.ai/okf/chapter/cbse-class-7-science-curiosity-light-shadows-and-reflections.md" source_type: "examSubjectBookChapter" source_id: "69bff571fb5daab696da613b" source_pdf: "https://edzy-ai.s3.ap-south-1.amazonaws.com/edzy-express-ts/01430733-ac0f-4041-9085-ccd651f9b981.pdf" source: "Edzy" version: 1 last_updated: "2026-06-20" --- # Light: Shadows and Reflections This chapter explores the nature of light, including its sources, properties, and the phenomena of shadows and reflections, blending practical activities with scientific principles to enhance understanding. --- ## Knowledge Snapshot | Field | Details | | :--- | :--- | | Class | Class 7 | | Subject | Science | | Book | Curiosity | | Chapter | Light: Shadows and Reflections | | Pages | 153-168 | --- ## Chapter Summary ### Short Summary The chapter discusses the properties of light, the sources of light, and the concepts of shadows and reflections through various activities and experiments. ### Detailed Summary Keshav experiences the beauty of light in nature during his summer vacation at Jatin's village, noticing the fireflies' light and pondering about light sources. It emphasizes that the Sun is the primary source of light on Earth and discusses luminous and non-luminous objects. Different activities illustrate how light travels in straight lines, how it interacts with various materials, and how images are formed in mirrors. By conducting experiments, readers learn about shadows, reflections, and the construction of optical devices like pinhole cameras. --- ## Topic-Wise Explanation ### Sources of Light The Sun, stars, lightning, natural fire, and certain animals are natural light sources. Luminous objects emit their own light, while non-luminous objects, such as the Moon, do not; they only reflect light from other sources. Modern LED lamps are highlighted for their efficiency and environmental benefits. ### Does Light Travel in a Straight Line? Experiments with matchboxes and a torch demonstrate that light travels in straight lines. A bent pipe experiment further confirms this principle, showing that light cannot bend. ### Light through Transparent, Translucent, and Opaque Materials Experiments classify objects based on their transparency. Light passes through transparent materials, is partially blocked by translucent materials, and does not pass through opaque materials. ### Shadow Formation Shadows are formed when an opaque object blocks light. Different activities illustrate how the size and shape of shadows can vary depending on the object and light source. ### Reflection of Light Experiments show that light changes direction when it hits shiny surfaces, which is known as reflection. Mirrors redirect light, leading to visible images. ### Images Formed in a Plane Mirror Looking into a mirror reveals reflections. Activities emphasize the sameness of size in images and explore lateral inversion. ### Pinhole Camera A pinhole camera uses a tiny hole to project images on a screen, illustrating key principles of light and image formation. ### Making Some Useful Items The chapter concludes by discussing the construction of periscopes and kaleidoscopes as applications of light principles, enhancing observation abilities. --- ## Character Analysis N/A --- ## Core Ideas | Idea | Explanation | | :--- | :--- | | Luminous Objects | Objects that emit their own light. | | Non-Luminous Objects | Objects that do not emit their own light. | | Shadow Formation | Dark patches formed when an object blocks light. | | Reflection of Light | Change in direction of light when it hits reflective surfaces. | --- ## Key Concepts | Concept | Meaning | | :--- | :--- | | Transparency | Ability of materials to allow light to pass through. | | Reflection | Bouncing back of light from surfaces. | | Shadows | Dark areas formed due to obstruction of light. | --- ## Important Points for Revision * The Sun is the main natural light source. * Fireflies communicate using light. * Light travels in straight lines. * Transparent materials allow light to pass, while opaque materials do not. * Shadows form when an object obstructs light. * Reflection is observed in mirrors and shiny surfaces. * A pinhole camera projects images using light. * Periscopes and kaleidoscopes utilize the reflection of light. --- ## Vocabulary and Glossary | Word / Phrase | Meaning | | :--- | :--- | | Luminous | Emitting light. | Non-luminous | Not emitting light. | Opaque | Not allowing light to pass through. | | Translucent | Allowing some light to pass through. | --- ## Practice Questions ### Short Answer Questions 1. What are luminous objects? 2. How does light travel according to the chapter? 3. What causes shadows to form? 4. Explain the principle of reflection of light. 5. What is the function of a pinhole camera? ### Long Answer Questions 1. Describe the various sources of light and categorize them. 2. Explain the experiments conducted to demonstrate that light travels in a straight line. 3. Discuss the significance of transparent, translucent, and opaque materials in relation to light. 4. How are images formed in a plane mirror? Include observations from the chapter’s activities. --- ## Related Concepts | Concept | Description | | :--- | :--- | | Periscopes | Optical devices using reflection to observe objects out of sight. | | Kaleidoscopes | Devices that use mirrors to create beautiful visual patterns. | --- ## Source Attribution | Field | Value | | :--- | :--- | | Source | Edzy | | Reference Type | examSubjectBookChapter | | Reference ID | 69bff571fb5daab696da613b | | Canonical URL | https://www.edzy.ai/cbse-class-7-science-curiosity-light-shadows-and-reflections | | Markdown URL | https://www.edzy.ai/okf/chapter/cbse-class-7-science-curiosity-light-shadows-and-reflections.md |