Important Questions Class 7 Science Chapter 7: Heat Transfer in Nature

Heat transfer is the movement of heat from a hotter region to a colder region.
Conduction, convection and radiation explain cooking, winds, clothing, houses and the water cycle.

Heat transfer explains how warmth moves through solids, liquids, gases and empty space. Important Questions Class 7 Science Chapter 7 help students practise conduction, good and poor conductors, convection, land breeze, sea breeze, radiation, heat absorption, water cycle, infiltration, groundwater and aquifers. The CBSE 2026 chapter explains these ideas through metal strips, smoke, heated water, coastal winds, sunlight, seepage and ice stupas.

Key Takeaways

• Conduction: Heat moves from hotter part to colder part without movement of particles.
• Convection: Heat moves through actual movement of particles in liquids and gases.
• Radiation: Heat travels without any material medium, as sunlight reaches Earth.
• Water Cycle: Water moves through evaporation, condensation, precipitation and infiltration.

Important Questions Class 7 Science Chapter 7 Structure 2026

Important Questions Class 7 Science Chapter 7 with Answers

Heat Transfer in Nature explains how heat moves through solids, liquids, gases and radiation.
Students should identify the method of heat transfer before writing an explanation.
These heat transfer in nature class 7 questions follow the NCERT 2026 chapter flow.

1. What does Important Questions Class 7 Science Chapter 7 mainly teach?

Important Questions Class 7 Science Chapter 7 mainly teach conduction, convection, radiation, water cycle, infiltration, groundwater and aquifers. The chapter links heat transfer with daily life and nature.

1. Conduction Skill: Explain heat flow in solids.
2. Convection Skill: Explain heat flow in liquids and gases.
3. Radiation Skill: Explain heat transfer without medium.
4. Water Cycle Skill: Explain evaporation, precipitation and groundwater recharge.
5. Final Result: Chapter 7 teaches heat transfer and water movement in nature.

2. What is the name of Class 7 Science Chapter 7?

The name of Class 7 Science Chapter 7 is Heat Transfer in Nature. It explains how heat moves and affects natural processes.

1. Chapter Number: 7.
2. Chapter Name: Heat Transfer in Nature.
3. Textbook: Curiosity.
4. Final Result: Chapter 7 is about heat transfer and water cycle.

3. Why is Kerala warmer and more humid than Gangtok in winter?

Kerala is warmer and more humid because it is closer to the equator and has a long coastline. Gangtok is in Sikkim, where winter is colder.

1. Kerala: Closer to the equator.
2. Coastline: Adds humidity.
3. Gangtok: Has colder winter conditions.
4. Final Result: Location affects temperature and humidity.

Class 7 Science Chapter 7 Important Questions

Class 7 Science Chapter 7 important questions focus on heat movement and natural examples.
The chapter uses cooking utensils, woollen clothes, winds, sunlight and groundwater to explain concepts.
Students should answer with process names and reasons.

4. What is heat transfer?

Heat transfer is the movement of heat from a hotter object or region to a colder one. It can occur by conduction, convection or radiation.

1. Hot Region: Gives heat.
2. Cold Region: Receives heat.
3. Methods: Conduction, convection and radiation.
4. Final Result: Heat moves from hot to cold regions.

5. What are the three modes of heat transfer?

The three modes of heat transfer are conduction, convection and radiation. They occur in different ways.

1. Conduction: Common in solids.
2. Convection: Occurs in liquids and gases.
3. Radiation: Does not require medium.
4. Final Result: Heat transfers by three main processes.

6. Why are cooking utensils generally made of metals?

Cooking utensils are made of metals because metals are good conductors of heat. They transfer heat quickly from flame to food.

1. Material: Metal.
2. Property: Good conductor of heat.
3. Use: Cooking.
4. Final Result: Metal utensils heat food efficiently.

7. Why are handles of cooking utensils often made of poor conductors?

Handles are made of poor conductors so that they do not become too hot quickly. This helps us hold utensils safely.

1. Utensil Body: Needs heat conduction.
2. Handle: Should reduce heat flow.
3. Safe Materials: Wood or plastic.
4. Final Result: Poor conductor handles protect hands from heat.

Conduction Class 7 Science Questions

Conduction class 7 science questions explain heat flow through direct contact.
It mainly occurs in solids.
Particles pass heat to neighbouring particles without moving away from their positions.

8. What is conduction of heat?

Conduction is heat transfer from the hotter part of an object to the colder part. The particles do not move from their positions.

1. Hot End: Receives heat first.
2. Neighbouring Particles: Pass heat onward.
3. Particle Movement: No movement from fixed positions.
4. Final Result: Conduction transfers heat through contact.

9. How does heat travel through a metal strip?

Heat travels through a metal strip from the heated end to the colder end. The wax melts near each pin as heat reaches it.

1. Heated End: Near candle flame.
2. First Pin: Falls first.
3. Next Pins: Fall later in order.
4. Final Result: Heat travels along the metal strip by conduction.

10. Why does the pin closest to the flame fall first?

The pin closest to the flame falls first because that region receives heat first. The wax holding it melts before the other wax drops.

1. Pin I: Nearest to flame.
2. Wax: Melts due to heat.
3. Other Pins: Heat reaches them later.
4. Final Result: Nearest pin falls first due to earlier heating.

11. Why do all pins on the metal strip not fall together?

All pins do not fall together because heat takes time to travel along the strip. The farther pins get heat later.

1. Heat Source: Candle.
2. Direction: Hot end to cold end.
3. Distance: Farther pins heat later.
4. Final Result: Pins fall one by one due to gradual heat conduction.

12. Why does heat transfer in solids mainly occur by conduction?

Heat transfer in solids mainly occurs by conduction because solid particles stay in fixed positions. They pass heat to neighbouring particles.

1. Solid Particles: Do not move freely.
2. Heat Passing: Occurs from particle to particle.
3. Main Process: Conduction.
4. Final Result: Solids transfer heat mainly by conduction.

Good Conductors of Heat Class 7 Questions

Good conductors of heat class 7 questions focus on materials that allow heat to pass easily.
Metals are common good conductors.
This property makes metals useful in cooking utensils.

13. What are good conductors of heat?

Good conductors of heat are materials that allow heat to pass through them easily. Metals are good conductors.

1. Common Example: Steel.
2. Common Example: Aluminium.
3. Use: Cooking utensils.
4. Final Result: Good conductors transfer heat easily.

14. Why is aluminium used in cooking vessels?

Aluminium is used in cooking vessels because it conducts heat well. It transfers heat quickly to food.

1. Material: Aluminium.
2. Property: Good conductor.
3. Application: Cooking.
4. Final Result: Aluminium helps food cook faster.

15. Why does a metal spoon become hot in hot tea?

A metal spoon becomes hot because heat travels through metal by conduction. The spoon conducts heat from the hot tea.

1. Hot Tea: Gives heat.
2. Metal Spoon: Conducts heat.
3. Handle End: Becomes warm.
4. Final Result: Metal spoon gets hot by conduction.

16. Give examples of good conductors of heat.

Steel, aluminium, iron and copper are good conductors of heat. They allow heat to pass easily.

1. Steel: Used in utensils.
2. Iron: Used in pans.
3. Copper: Used in some vessels.
4. Final Result: Metals are usually good conductors of heat.

Poor Conductors of Heat Class 7 Questions

Poor conductors of heat class 7 questions explain materials that do not allow heat to pass easily.
They are also called insulators.
Wood, glass, clay, porcelain and air are common poor conductors.

17. What are poor conductors of heat?

Poor conductors of heat are materials that do not allow heat to pass through them easily. They are also called insulators.

1. Wood: Poor conductor.
2. Glass: Poor conductor.
3. Air: Poor conductor.
4. Final Result: Poor conductors slow heat transfer.

18. Why do pins not fall from a wooden strip in the conduction activity?

Pins do not fall because wood is a poor conductor of heat. Heat does not travel easily along the wooden strip.

1. Material: Wood.
2. Property: Poor heat conductor.
3. Wax: Does not melt quickly.
4. Final Result: Wood does not conduct enough heat to drop the pins.

19. Why does tea stay hot longer in clay or porcelain cups?

Tea stays hot longer because clay and porcelain are poor conductors of heat. They reduce heat loss from hot tea.

1. Cup Material: Clay or porcelain.
2. Property: Poor conductor.
3. Effect: Heat escapes slowly.
4. Final Result: Clay and porcelain cups keep tea hot longer.

20. Why do woollen clothes keep us warm?

Woollen clothes keep us warm because wool traps air in its pores. Air is a poor conductor of heat.

1. Wool Fabric: Has tiny spaces.
2. Trapped Air: Acts as insulator.
3. Heat Loss: Reduces from body.
4. Final Result: Wool keeps the body warm by trapping air.

21. Why are two thin blankets warmer than one thick blanket?

Two thin blankets are warmer because air gets trapped between their layers. Trapped air acts as a poor conductor of heat.

1. Blanket Layers: Create air space.
2. Air: Poor conductor.
3. Heat Flow: Reduced from body.
4. Final Result: Trapped air between blankets improves insulation.

22. Why are hollow bricks used in house walls?

Hollow bricks are used because trapped air inside them acts as an insulator. This keeps houses warmer in winter and cooler in summer.

1. Hollow Space: Contains air.
2. Air: Poor conductor.
3. House Effect: Reduces heat exchange.
4. Final Result: Hollow bricks reduce heat transfer through walls.

Convection Class 7 Science Questions

Convection class 7 science questions explain heat transfer in liquids and gases.
In convection, particles actually move from one place to another.
Hot fluid rises, and cooler fluid moves down to take its place.

23. What is convection?

Convection is heat transfer by actual movement of particles in liquids and gases. Heated particles become lighter and rise.

1. Medium: Liquid or gas.
2. Hot Fluid: Rises.
3. Cool Fluid: Moves down.
4. Final Result: Convection transfers heat through particle movement.

24. Why does smoke rise up from burning firewood?

Smoke rises because it is warmer than the surrounding air. Warm gases expand, become lighter and move upward.

1. Burning Firewood: Produces warm smoke.
2. Warm Air: Expands.
3. Density: Becomes lighter.
4. Final Result: Smoke rises due to convection.

25. Why does the paper cup rise when a candle is placed below it?

The paper cup rises because air below it gets heated and becomes lighter. The warm air rises and pushes the cup upward.

1. Candle Flame: Heats air.
2. Air: Expands.
3. Warm Air: Rises.
4. Final Result: The cup rises due to rising hot air.

26. Why does a balloon become larger when kept in the Sun?

A balloon becomes larger because air inside it gets heated and expands. The expanded air occupies more space.

1. Sunlight: Heats the air.
2. Air Inside: Expands.
3. Balloon Size: Increases.
4. Final Result: Heating makes air expand.

27. How does heat transfer in water by convection?

Water at the bottom gets heated, expands, becomes lighter and rises. Cooler water comes down and gets heated.

1. Bottom Water: Heated by flame.
2. Hot Water: Rises.
3. Cool Water: Moves down.
4. Cycle: Continues until water heats up.
5. Final Result: Water heats by convection currents.

28. Why does the coloured streak rise in heated water?

The coloured streak rises because the water at the bottom becomes hot and lighter. It moves upward with the heated water.

1. Potassium Permanganate: Shows water movement.
2. Hot Water: Rises in middle.
3. Cool Water: Comes down from sides.
4. Final Result: The coloured streak shows convection in water.

29. Why does convection not happen in solids?

Convection does not happen in solids because solid particles cannot move freely from one place to another. They remain in fixed positions.

1. Solid Particles: Fixed positions.
2. Convection Need: Actual particle movement.
3. Main Heat Transfer: Conduction.
4. Final Result: Solids do not transfer heat by convection.

Land and Sea Breeze Class 7 Questions

Land and sea breeze class 7 questions explain wind movement in coastal areas.
Land heats and cools faster than water.
This difference creates sea breeze during the day and land breeze at night.

30. Why does soil heat faster than water?

Soil heats faster than water because land and water absorb and lose heat at different rates. In the activity, soil temperature rises more in 20 minutes.

1. Sunlight: Falls on both soil and water.
2. Soil: Temperature rises faster.
3. Water: Temperature rises slower.
4. Final Result: Soil heats faster than water.

31. Why does soil cool faster than water?

Soil cools faster because land loses heat faster than water. After heating, soil temperature falls more quickly.

1. Heated Soil: Loses heat fast.
2. Heated Water: Cools slowly.
3. Coastal Effect: Creates night breeze.
4. Final Result: Soil cools faster than water.

32. What is sea breeze?

Sea breeze is the movement of cooler air from the sea towards the land during the day. It happens because land heats faster than water.

1. Daytime: Land becomes hotter.
2. Warm Air: Rises above land.
3. Cool Air: Moves from sea to land.
4. Final Result: Sea breeze blows from sea to land.

33. Why does sea breeze occur during the day?

Sea breeze occurs because land becomes warmer than the sea during the day. Warm air above land rises, and cooler sea air moves in.

1. Land: Heats faster.
2. Sea: Remains cooler.
3. Air Movement: Sea to land.
4. Final Result: Daytime temperature difference causes sea breeze.

34. What is land breeze?

Land breeze is the movement of cooler air from land towards the sea at night. It happens because land cools faster than water.

1. Night: Land becomes cooler.
2. Sea: Remains warmer.
3. Air Movement: Land to sea.
4. Final Result: Land breeze blows from land to sea.

35. Why does land breeze occur at night?

Land breeze occurs because land cools down faster than the sea at night. Warm air above the sea rises, and cooler land air moves towards the sea.

1. Land: Cools quickly.
2. Sea: Stays warmer.
3. Cool Air: Moves from land to sea.
4. Final Result: Night temperature difference causes land breeze.

36. Why do coastal houses often have windows facing the sea?

Coastal houses have windows facing the sea to receive sea breeze during the day. Sea breeze gives relief from heat.

1. Daytime: Sea breeze enters from sea side.
2. Air: Cooler than land air.
3. Comfort: Reduces heat.
4. Final Result: Sea-facing windows help cool coastal houses.

Radiation Class 7 Science Questions

Radiation class 7 science questions explain heat transfer without a medium.
Heat from the Sun reaches Earth by radiation.
All objects radiate heat to their surroundings.

37. What is radiation?

Radiation is heat transfer that does not require any material medium. Heat from the Sun reaches Earth by radiation.

1. Medium: Not required.
2. Example: Sunlight warms Earth.
3. Daily Example: Warmth near a fire.
4. Final Result: Radiation transfers heat without medium.

38. How does heat from a fireplace reach us?

Heat from a fireplace reaches us directly by radiation. The warmth travels from the hot fire to our body.

1. Hot Object: Fire.
2. Receiver: Person sitting nearby.
3. Process: Radiation.
4. Final Result: Fire warms us mainly through radiation.

39. How does heat from the Sun reach Earth?

Heat from the Sun reaches Earth by radiation. No material medium is needed between the Sun and Earth.

1. Source: Sun.
2. Space: No air needed.
3. Process: Radiation.
4. Final Result: Solar heat reaches Earth through radiation.

40. Why does a hot utensil cool after being kept away from flame?

A hot utensil cools because it radiates heat to its surroundings. It also loses heat through contact with air and surface.

1. Utensil: Hot object.
2. Surroundings: Cooler.
3. Heat Loss: Radiation occurs.
4. Final Result: Hot objects cool by giving heat to surroundings.

41. Why are white clothes comfortable in summer?

White or light-coloured clothes are comfortable because they reflect most heat falling on them. This reduces heat absorption.

1. Light Colours: Reflect heat.
2. Heat Absorption: Less.
3. Season: Summer.
4. Final Result: Light clothes keep us cooler in summer.

42. Why are dark clothes preferred in winter?

Dark clothes are preferred in winter because dark surfaces absorb more heat. This helps us feel warmer.

1. Dark Colours: Absorb heat.
2. Heat Gain: More.
3. Season: Winter.
4. Final Result: Dark clothes absorb more heat in winter.

43. Which heat transfer methods occur while heating water in a pan?

Conduction, convection and radiation occur while heating water in a pan. Heat reaches the pan, water and surroundings through different methods.

1. Conduction: Flame heats the metal pan.
2. Convection: Water circulates and heats up.
3. Radiation: Warmth is felt near flame and pan.
4. Final Result: All three heat transfer modes occur during cooking.

Water Cycle Class 7 Questions

Water cycle class 7 questions explain the continuous movement of water on Earth.
The Sun provides heat for evaporation.
Cloud formation and precipitation return water to Earth.

44. What is the water cycle?

The water cycle is the continuous movement of water upward as vapour and downward as precipitation. It returns water to oceans, rivers, lakes, soil and rocks.

1. Upward Movement: Evaporation and transpiration.
2. Cloud Formation: Condensation.
3. Downward Movement: Rain, snow or hail.
4. Final Result: Water cycle redistributes water on Earth.

45. What are the main processes in the water cycle?

The main processes are evaporation, transpiration, condensation, precipitation and infiltration. These processes move water through air, land and water bodies.

1. Evaporation: Water changes into vapour.
2. Condensation: Vapour forms clouds.
3. Precipitation: Water falls as rain, snow or hail.
4. Final Result: Water cycle includes upward and downward water movement.

46. What is evaporation in the water cycle?

Evaporation is the process in which water changes into water vapour due to heat. The Sun heats oceans, rivers and lakes.

1. Heat Source: Sun.
2. Water Bodies: Oceans, rivers and lakes.
3. Change: Liquid water becomes vapour.
4. Final Result: Evaporation sends water vapour into air.

47. What is transpiration?

Transpiration is the loss of water vapour from plants and trees. It adds water vapour to the atmosphere.

1. Source: Plants.
2. Form: Water vapour.
3. Role: Adds moisture to air.
4. Final Result: Transpiration releases water vapour from plants.

48. What is condensation in the water cycle?

Condensation is the cooling of water vapour to form tiny water droplets. These droplets form clouds.

1. Water Vapour: Rises up.
2. Cooling: Happens at higher altitude.
3. Clouds: Form from droplets.
4. Final Result: Condensation forms clouds.

49. What is precipitation?

Precipitation is the falling of water from clouds as rain, snow or hail. It brings water back to Earth.

1. Rain: Liquid water.
2. Snow: Frozen water crystals.
3. Hail: Ice pellets.
4. Final Result: Precipitation returns water to Earth.

50. How does the water cycle help Earth?

The water cycle redistributes and replenishes water in rivers, lakes and oceans. It also conserves the total amount of water on Earth.

1. Rivers: Get replenished.
2. Lakes: Receive water.
3. Ground: Receives infiltrated water.
4. Final Result: Water cycle maintains water movement on Earth.

Infiltration Class 7 Science Questions

Infiltration class 7 science questions explain how surface water seeps into soil and rocks.
The rate of seepage depends on spaces between particles.
Water moves fastest through gravel and slowest through clay.

51. What is infiltration?

Infiltration is the process of surface water seeping through soil and rocks. It helps recharge groundwater.

1. Water Source: Rainwater or surface water.
2. Path: Soil and rocks.
3. Result: Water goes underground.
4. Final Result: Infiltration sends surface water below the ground.

52. Through which material does water seep fastest?

Water seeps fastest through gravel. Gravel has wider spaces between particles.

1. Material: Gravel.
2. Spaces: Wide and connected.
3. Seepage: Fast.
4. Final Result: Gravel allows fastest water seepage.

53. Through which material does water seep slowest?

Water seeps slowest through clay. Clay has very small spaces between particles.

1. Material: Clay.
2. Spaces: Very small.
3. Seepage: Very slow.
4. Final Result: Clay allows slowest seepage.

54. Why does water seep differently through clay, sand and gravel?

Water seeps differently because particle spaces differ. Wider, open and connected spaces allow faster water movement.

1. Gravel: Wide spaces.
2. Sand: Smaller spaces than gravel.
3. Clay: Very small spaces.
4. Final Result: Particle space controls seepage rate.

55. Why do concrete surfaces reduce infiltration?

Concrete surfaces reduce infiltration because they cover soil and block water from entering the ground. This limits groundwater recharge.

1. Concrete: Hard surface.
2. Rainwater: Runs off.
3. Groundwater Recharge: Reduces.
4. Final Result: Concrete surfaces limit water seepage into ground.

Groundwater Class 7 Questions

Groundwater class 7 questions explain water stored below Earth’s surface.
It comes from water that seeps through soil and rocks.
Wells and bore wells are used to extract groundwater.

56. What is groundwater?

Groundwater is water stored in pore spaces of sediments and openings in rocks below Earth’s surface. It comes from infiltrated water.

1. Location: Beneath the ground.
2. Storage: Pores and rock openings.
3. Source: Seeped surface water.
4. Final Result: Groundwater is underground stored water.

57. How does rainwater become groundwater?

Rainwater becomes groundwater when it seeps through soil and rocks. It gets stored in pore spaces and rock openings underground.

1. Rain: Falls on surface.
2. Infiltration: Water seeps down.
3. Storage: Pore spaces and rocks.
4. Final Result: Infiltration converts surface water into groundwater.

58. How do wells and handpumps get water?

Wells and handpumps get water from underground water stored in aquifers. This water may lie from a few metres to hundreds of metres below ground.

1. Water Source: Groundwater.
2. Storage Layer: Aquifer.
3. Extraction: Wells or bore wells.
4. Final Result: Wells and handpumps draw groundwater.

59. Why is groundwater getting depleted?

Groundwater is getting depleted due to excessive extraction, reduced vegetation cover and more concrete surfaces. These reduce recharge.

1. Population: Increases water demand.
2. Extraction: More groundwater is pumped.
3. Concrete: Reduces infiltration.
4. Final Result: Groundwater depletion occurs when use exceeds recharge.

60. How can groundwater be replenished?

Groundwater can be replenished through rainwater harvesting and recharge pits. These methods help water seep into the ground.

1. Rainwater Harvesting: Stores rainwater.
2. Recharge Pits: Help infiltration.
3. Purpose: Refill underground water.
4. Final Result: Recharge methods help restore groundwater.

Aquifer Class 7 Science Questions

Aquifer class 7 science questions explain underground storage layers.
Aquifers contain sediments and rocks with pore spaces.
They store the water extracted by wells and bore wells.

61. What is an aquifer?

An aquifer is an underground layer of sediments and rocks that stores water in pore spaces. It is an important groundwater source.

1. Location: Beneath Earth’s surface.
2. Material: Sediments and rocks.
3. Storage: Pore spaces.
4. Final Result: Aquifers store groundwater underground.

62. Why are aquifers important?

Aquifers are important because they store groundwater used by wells and bore wells. They support water needs in many places.

1. Storage: Groundwater.
2. Use: Drinking and farming.
3. Extraction: Wells and bore wells.
4. Final Result: Aquifers supply usable groundwater.

63. What type of spaces help aquifers store water?

Wide, open and connected spaces help aquifers store water. Water moves and stays more easily in such spaces.

1. Wide Spaces: Allow movement.
2. Open Spaces: Permit entry.
3. Connected Spaces: Allow flow.
4. Final Result: Connected pore spaces store groundwater effectively.

64. Why is groundwater not unlimited?

Groundwater is not unlimited because extraction can be faster than recharge. Growing population and reduced infiltration increase depletion.

1. Extraction: Pumping removes water.
2. Recharge: Needs rainfall and infiltration.
3. Urban Surfaces: Reduce seepage.
4. Final Result: Groundwater must be used carefully.

NCERT Class 7 Science Chapter 7 Questions

NCERT Class 7 Science Chapter 7 questions test conduction, convection, radiation, seepage and water cycle.
Students should use process names and activity observations in answers.
These NCERT Class 7 Science Chapter 7 questions follow the 2026 exercise pattern.

65. In a saucepan, which material should form the body and handle?

The body should be a good conductor, and the handle should be a poor conductor. This helps cooking and safe handling.

1. Saucepan Body: Good conductor.
2. Handle: Poor conductor.
3. Reason: Heat food while protecting hands.
4. Final Result: Body should conduct heat, handle should insulate.

66. In the pin and wax activity, which pins fall first?

Pins I and II fall earlier than pins III and IV. Pins closer to the heated end receive heat first.

1. Heat Source: Candle.
2. Nearest Pins: I and II.
3. Farther Pins: III and IV.
4. Final Result: Pins near the flame fall first.

67. Where should a smoke detector be fitted in a room?

A smoke detector should be fitted on the ceiling. Smoke rises because it is warmer than surrounding air.

1. Smoke: Warm mixture of gases and tiny particles.
2. Movement: Rises upward.
3. Best Place: Ceiling.
4. Final Result: Ceiling is the most suitable place for a smoke detector.

68. Will keeping a leaky lassi tumbler inside another tumbler keep lassi cold longer?

Yes, it can help keep lassi cold longer. Air trapped between the two tumblers acts as a poor conductor of heat.

1. Outer Tumbler: Creates an air gap.
2. Air: Poor conductor.
3. Heat Entry: Slows down.
4. Final Result: The air gap helps insulate cold lassi.

69. Is heat transfer in solids through convection true or false?

It is false because heat transfer in solids mainly occurs through conduction. Solid particles do not move freely.

1. Solids: Particles fixed.
2. Convection: Needs particle movement.
3. Correct Process: Conduction.
4. Final Result: Solids mainly transfer heat by conduction.

70. Is convection heat transfer by actual movement of particles true or false?

It is true because convection occurs through movement of liquid or gas particles. Hot particles rise and cooler particles sink.

1. Medium: Liquid or gas.
2. Particle Movement: Actual movement occurs.
3. Example: Heated water circulation.
4. Final Result: Convection needs movement of particles.

71. Do clay areas allow more seepage than sandy areas?

No, clay areas allow less seepage than sandy areas. Clay has smaller spaces between particles.

1. Clay: Very slow seepage.
2. Sand: Slow but faster than clay.
3. Reason: Particle spaces differ.
4. Final Result: Sandy areas allow more seepage than clay areas.

72. Is movement of cooler air from land to sea called land breeze?

Yes, movement of cooler air from land to sea is called land breeze. It occurs at night.

1. Time: Night.
2. Direction: Land to sea.
3. Cause: Land cools faster.
4. Final Result: Land breeze blows from land to sea.

73. Where do ice cubes get heat to melt in a dish?

Ice cubes get heat from the surrounding air and dish. Heat moves from warmer surroundings to colder ice.

1. Ice: Colder.
2. Surroundings: Warmer.
3. Heat Flow: Towards ice.
4. Final Result: Ice melts by taking heat from surroundings.

74. In which direction does smoke move if an incense stick points downwards?

Smoke still moves upward. It is warmer than surrounding air and rises due to convection.

1. Incense Smoke: Warm.
2. Density: Lower than surrounding air.
3. Movement: Upward.
4. Final Result: Smoke rises even if the incense stick points down.

75. Why are hollow bricks used in hot regions?

Hollow bricks are used because air trapped inside them reduces heat transfer. They keep houses cooler in summer and warmer in winter.

1. Hollow Bricks: Trap air.
2. Air: Poor conductor.
3. Climate Comfort: Reduces outside heat effect.
4. Final Result: Hollow bricks act as insulation.

76. How do large water bodies prevent extreme temperature?

Large water bodies heat and cool slowly. They moderate the temperature of nearby areas.

1. Day: Water heats slower than land.
2. Night: Water cools slower than land.
3. Effect: Temperature changes reduce.
4. Final Result: Large water bodies reduce extreme temperature changes.

Class 7 Science Chapter 7 Questions and Answers

Class 7 Science Chapter 7 questions and answers should connect classroom activities with natural processes.
Every answer should mention the correct heat transfer method or water movement process.
These answers support quick revision for school tests.

77. Why does wet cloth dry faster on a sunny day?

Wet cloth dries faster on a sunny day because heat from the Sun increases evaporation. Water changes into vapour faster.

1. Sunlight: Provides heat.
2. Water: Evaporates from cloth.
3. Sunny Day: Faster evaporation.
4. Final Result: Sun’s radiation speeds up drying.

78. How does water seep through Earth and get stored underground?

Water seeps through soil and rocks by infiltration. It gets stored in pore spaces and rock openings as groundwater.

1. Surface Water: Enters soil.
2. Path: Moves through spaces.
3. Storage: Aquifers.
4. Final Result: Infiltration stores water as groundwater.

79. How does the water cycle replenish water on Earth?

The water cycle replenishes water through evaporation, condensation and precipitation. Rainwater returns to rivers, lakes, oceans and underground sources.

1. Evaporation: Sends vapour upward.
2. Precipitation: Brings water down.
3. Infiltration: Recharges groundwater.
4. Final Result: Water cycle redistributes and replenishes water.

80. What is an ice stupa?

An ice stupa is a cone-shaped ice structure made in Ladakh during winter. It melts slowly in spring and provides water.

1. Place: Ladakh.
2. Season Made: Winter.
3. Use: Supplies water in spring and summer.
4. Final Result: Ice stupas conserve water for dry periods.

81. Why does paper wrapped on a rotating metal rod not burn easily?

Paper does not burn easily because heat transfers quickly from paper to the metal rod. Metal conducts heat away from the paper.

1. Metal Rod: Good conductor.
2. Paper: Loses heat to metal.
3. Rotation: Spreads heat.
4. Final Result: Metal conduction prevents paper from reaching burning temperature quickly.

82. Why does a paper spiral rotate above a candle?

The paper spiral rotates because hot air from the candle rises. Rising air pushes the spiral and makes it turn.

1. Candle: Heats air.
2. Hot Air: Rises upward.
3. Spiral: Moves due to air current.
4. Final Result: Convection makes the paper spiral rotate.

Class 7 Science Important Links