Time: 2 Hours
Maximum Marks: 80
Section A: Fill in the Blanks (10 × 1 = 10 marks)
- Light travels in a __________ line.
- The Sun is a __________ source of light.
- The Moon is a __________ source of light.
- Shadows are formed when an object __________ light.
- The part of a shadow that is darkest is called __________.
- A __________ is an object that allows light to pass through.
- __________ objects do not allow light to pass through.
- The change in the size and position of a shadow is due to the __________ of light.
- The bending of light when it passes from one medium to another is called __________.
- A periscope works on the principle of __________.
Section B: Multiple Choice Questions (10 × 1 = 10 marks)
- Which of the following is a luminous object? a) Moon b) Sun c) Chair d) Book
- Which material is transparent? a) Glass b) Wood c) Metal d) Stone
- What is the darkest part of a shadow called? a) Penumbra b) Umbra c) Shade d) Reflection
- Which of the following causes shadow formation? a) Reflection b) Obstruction of light c) Refraction d) Diffraction
- Which phenomenon allows a straw in water to appear bent? a) Reflection b) Refraction c) Dispersion d) Absorption
- Which of the following is opaque? a) Air b) Glass c) Cardboard d) Water
- The size of a shadow increases when: a) Light source is far b) Object moves closer to light c) Object moves away from light d) Light is dim
- Which device helps to see objects around corners? a) Telescope b) Periscope c) Microscope d) Magnifying glass
- When light falls on a smooth surface, it __________. a) Refracts b) Reflects c) Disperses d) Absorbs
- Which color absorbs most light? a) White b) Black c) Yellow d) Blue
Section C: True or False (8 × 1 = 8 marks)
- Light travels in straight lines.
- Shadows are formed in transparent objects.
- Reflection occurs when light bounces off a surface.
- Refraction is the bending of light.
- The Sun is a natural source of light.
- A mirror is opaque.
- The size of a shadow depends on the position of the light source.
- Luminous objects do not produce their own light.
Section D: Match the Following (6 × 1 = 6 marks)
| Column A | Column B |
|---|---|
| 1. Umbra | a) Partial shadow |
| 2. Penumbra | b) Darkest part of shadow |
| 3. Transparent | c) Lets light pass through completely |
| 4. Opaque | d) Does not allow light to pass |
| 5. Refraction | e) Bending of light |
| 6. Reflection | f) Bouncing of light |
Section E: One Word Answer (8 × 1 = 8 marks)
- Natural source of light
- Object that produces its own light
- Object that allows some light to pass through
- Object that does not allow light to pass
- Bending of light
- Bouncing of light
- Dark part of a shadow
- Tool to see objects around corners
Section F: Short Answer Questions (8 × 3 = 24 marks)
- Define luminous and non-luminous objects with examples.
- Explain how shadows are formed.
- What is reflection? Give an example.
- What is refraction? Give an example.
- Explain how the size of a shadow change.
- Write three uses of mirrors in daily life.
- Difference between transparent, translucent, and opaque objects.
- How does a periscope help submarines?
Section G: Long Answer Questions (5 × 4 = 20 marks)
- Explain the properties of light.
- Describe the formation of shadows with diagram.
- Explain reflection and refraction with examples.
- Explain how lenses bend light.
- Importance of light in daily life.
Section H: Case-Based Questions (3 × 5 = 15 marks)
Case Study 1: Ria noticed that her shadow was longer in the morning and shorter at noon.
a) Why does the size of shadow change? b) What happens when the Sun is overhead? c) Explain why the shadow is longer in the morning. d) Give one example of shadow formation at home.
Case Study 2: A student placed a pencil in a glass of water and observed it appeared bent.
a) Which phenomenon is observed? b) Explain why the pencil appears bent. c) Name two examples where this phenomenon is seen. d) Why does light bend when it passes from one medium to another?
Case Study 3: In a physics lab, a student used a mirror to reflect sunlight onto a wall.
a) Which property of light is being used? b) Explain the experiment. c) Name two devices that use reflection of light. d) Why is reflection important in daily life?
Section I: Diagram-Based Questions (2 × 4 = 8 marks)
- Draw a diagram showing shadow formation and label umbra and penumbra.
- Draw and label the path of light showing refraction through a glass of water.
ANSWER KEY
Section A: Fill in the Blanks (Detailed)
- Straight – Light travels in straight lines unless it passes through different mediums.
- Natural – The Sun is a natural source of light.
- Non-luminous – The Moon reflects light from the Sun but does not produce its own light.
- Obstructs – Shadows form when an opaque object obstructs light.
- Umbra – The darkest part of the shadow where no light reaches.
- Transparent object – Lets light pass through completely.
- Opaque objects – Do not allow light to pass through.
- Angle/direction – Shadow size changes due to position or angle of the light source.
- Refraction – Bending of light when it moves from one medium to another.
- Reflection – A periscope uses mirrors to reflect light to the viewer.
Section B: Multiple Choice Questions
- b) Sun – It produces its own light.
- a) Glass – Light passes through completely.
- b) Umbra – The darkest part of a shadow.
- b) Obstruction of light – Shadows are formed when light is blocked.
- b) Refraction – Light bends as it passes between media.
- c) Cardboard – Light cannot pass through it.
- b) Object moves closer to light – Shadow becomes larger.
- b) Periscope – Uses mirrors to see around obstacles.
- b) Reflects – Light bounces off smooth surfaces.
- b) Black – Absorbs most light and heat.
Section C: True or False
- True
- False – Transparent objects allow light, so no shadow forms.
- True – Light bounces off reflective surfaces.
- True – Light bends in refraction.
- True – The Sun emits its own light.
- False – Mirrors are reflective, not opaque.
- True – Shadow size changes with the light source position.
- False – Luminous objects produce their own light.
Section D: Match the Following
1 – b) Umbra – Darkest part of shadow
2 – a) Penumbra – Partial shadow
3 – c) Transparent – Lets light pass completely
4 – d) Opaque – Blocks all light
5 – e) Refraction – Bending of light
6 – f) Reflection – Bouncing of light
Section E: One Word Answer
- Sun
- Bulb or candle
- Translucent object
- Opaque object
- Refraction
- Reflection
- Umbra
- Periscope
Section F: Short Answer Questions (Detailed)
- Luminous vs Non-luminous: Luminous objects emit light (Sun, bulb), Non-luminous objects reflect light (Moon, book).
- Shadow formation: Shadows form behind opaque objects when light is blocked. Shape and size depend on object and light source.
- Reflection: Bouncing back of light from a surface, e.g., mirror reflects sunlight.
- Refraction: Bending of light when it passes from one medium to another. Example: Pencil in water appears bent.
- Shadow size: Larger when object is closer to light, smaller when further away.
- Uses of mirrors: Vehicles (rear-view mirrors), telescopes, periscopes.
- Transparency types: Transparent (lets all light), Translucent (some light), Opaque (no light).
- Periscope usage: Uses mirrors to see objects over obstacles, helps submarines observe without surfacing.
Section G: Long Answer Questions (Detailed)
- Explain the properties of light.
- Light travels in straight lines in a uniform medium unless it encounters another medium where refraction occurs.
- It can reflect off smooth surfaces, such as mirrors, enabling us to see images.
- Light bends (refracts) when it passes from one medium to another, e.g., air to water.
- It can disperse into a spectrum of colors through a prism.
- Light allows us to see objects, gives direction, supports photosynthesis in plants, and is essential for all life forms.
- Describe the formation of shadows with diagram.
- Shadows are formed when an opaque object blocks the path of light from a source.
- The darkest part of the shadow, called the umbra, receives no light.
- The lighter part around the umbra is called the penumbra, which receives partial light.
- The size and shape of a shadow change depending on the distance and angle of the light source relative to the object.
- Diagram (to draw): Light rays from source → Object → Umbra (darkest region) and Penumbra (partial shadow) on the surface.
- Explain reflection and refraction with examples.
- Reflection: Occurs when light bounces off a surface. Example: A mirror reflects sunlight to a wall.
- Refraction: Occurs when light bends while entering a different medium due to change in speed. Example: Pencil in a glass of water appears bent.
- Reflection helps in seeing images, periscopes, telescopes; refraction helps in lenses, magnifying glasses, and vision correction.
- Explain how lenses bend light.
- Lenses work on the principle of refraction. Convex lenses converge parallel rays to a focus point, used in magnifying glasses, cameras, and telescopes.
- Concave lenses diverge parallel rays outward, used in corrective glasses for myopia (short-sightedness).
- Lenses help in magnification, focusing light, and forming clear images on screens or the retina.
- Importance of light in daily life.
- Enables vision: We see objects only because of light.
- Supports plant life: Photosynthesis requires sunlight.
- Energy source: Solar energy is derived from sunlight.
- Safety: Street lights, headlights, and signaling rely on light.
- Technology: Cameras, microscopes, telescopes, and optical instruments depend on light.
- Daily activities: Reading, working, and moving safely indoors and outdoors depend on proper light.
Section H: Case-Based Questions (Detailed)
Case 1: Shadow length changes due to Sun position. Shadow shortest at noon, longest in morning. Example: Tree shadow in backyard.
Case 2: Pencil appears bent – Refraction. Light changes speed between air and water. Examples: Spoon in water, coin in glass.
Case 3: Mirror experiment – Reflection of light. Devices: Periscope, telescope. Reflection important for seeing, signaling, and navigation.
Section I: Diagram-Based Questions
- Shadow diagram: Shows opaque object, light rays, umbra and penumbra, light source, surface.
- Refraction diagram: Shows pencil in water, incident ray, refracted ray, apparent position labeled.