---
title: "NCERT Solutions Class 7 Science Chapter 7 Heat Transfer in Nature"
url: https://www.swavid.com/science/class/7/chapter/heat-transfer-in-nature/ncert-solutions
dateModified: 2026-10-07T16:08:29+00:00
---

# NCERT Solutions Class 7 Science Chapter 7 Heat Transfer in Nature

This chapter's questions cover concepts related to heat transfer processes such as conduction, convection, and radiation, as well as natural phenomena like sea/land breezes, the water cycle, and groundwater seepage.

Free PDF (6 pages): https://www.swavid.com/api/seo/pdf/ncert/science/class-7/swavid-ncert-solutions-class-7-science-chapter-7-heat-transfer-in-nature-37ca7dad71.pdf

## Let Us Enhance Our Learning

### Question 1 (i)

*1 mark · MCQ*

Your father bought a saucepan made of two different materials, A and B, as shown in Fig. 7.14. The materials A and B have the following properties —

- Both A and B are good conductors of heat
- Both A and B are poor conductors of heat
- A is a good conductor and B is a poor conductor of heat
- A is a poor conductor and B is a good conductor of heat

**Solution**

1. A saucepan is used for cooking food, so its base needs to transfer heat quickly from the flame, meaning material A should be a good conductor (like metal).
2. The handle of the saucepan needs to be held safely without burning the hand, so material B should be a poor conductor (insulator) of heat.

**Answer:** (c) A is a good conductor and B is a poor conductor of heat

> Common mistake: Confusing the properties of the base and the handle of cooking utensils.

### Question 1 (ii)

*1 mark · MCQ*

Pins are stuck to a metal strip with wax and a burning candle is kept below the rod, as shown in Fig. 7.15. Which of the following will happen?

- All the pins will fall almost at the same time
- Pins I and II will fall earlier than pins III and IV
- Pins I and II will fall later than pins III and IV
- Pins II and III will fall almost at the same time

**Solution**

1. Heat is transferred along the metal strip by conduction from the heated end towards the colder end.
2. Pin I is closest to the candle flame, so the wax melts there first, followed by pins II, III, and IV in order.

**Answer:** (b) Pins I and II will fall earlier than pins III and IV

> Common mistake: Assuming all pins fall at the same time ignoring the direction of heat travel.

### Question 1 (iii)

*1 mark · MCQ*

A smoke detector is a device that detects smoke and sounds an alarm. Suppose you are fitting a smoke detector in your room. The most suitable place for this device will be:

- Near the floor
- In the middle of a wall
- On the ceiling
- Anywhere in the room

**Solution**

1. Smoke consists of hot gases and tiny particles which are warmer than the surrounding air and thus rise up due to convection.
2. Therefore, the most suitable place to install a smoke detector is on the ceiling where rising smoke accumulates first.

**Answer:** (c) On the ceiling

> Common mistake: Placing the smoke detector near the floor or wall.

### Question 2

*3 marks · Short answer*

A shopkeeper serves you cold lassi in a tumbler. By chance, the tumbler had a small leak. You were given another tumbler by the shopkeeper to put the leaky tumbler in it. Will this arrangement help to keep the lassi cold for a longer time? Explain.

**Solution**

1. Yes, this arrangement will help to keep the lassi cold for a longer time.
2. When the leaky tumbler is placed inside another tumbler, a layer of air gets trapped between the two tumblers.
3. Since air is a poor conductor of heat (an insulator), it reduces the flow of heat from the warmer surroundings to the cold lassi.

**Answer:** Yes, putting the leaky tumbler inside another tumbler traps air between them, which acts as an insulator and slows down heat transfer from outside.

> Common mistake: Forgetting that trapped air acts as an insulator.

### Question 3 (i)

*1 mark · True or false*

Heat transfer takes place in solids through convection.

**Solution**

1. In solids, heat transfer takes place mainly through conduction, not convection.

**Answer:** False

> Common mistake: Confusing conduction in solids with convection in fluids.

### Question 3 (ii)

*1 mark · True or false*

Heat transfer through convection takes place by the actual movement of particles.

**Solution**

1. Heat transfer through convection involves the actual movement of particles of liquids and gases.

**Answer:** True

> Common mistake: Thinking particles remain stationary in convection.

### Question 3 (iii)

*1 mark · True or false*

Areas with clay materials allow more seepage of water than those with sandy materials.

**Solution**

1. The statement is False.
2. Corrected statement: Areas with sandy materials allow more seepage of water than those with clay materials because the spaces between sand and gravel particles are wider.

**Answer:** False

> Common mistake: Students often confuse the seepage rate of clay and sand, forgetting that clay particles are very fine and tightly packed.

### Question 3 (iv)

*1 mark · True or false*

The movement of cooler air from land to sea is called land breeze.

**Solution**

1. The statement is True.

**Answer:** True

> Common mistake: Confusing land breeze with sea breeze.

### Question 4

*3 marks · Short answer*

Some ice cubes placed in a dish melt into water after sometime. Where do the ice cubes get heat for this transformation?

**Solution**

1. Ice cubes kept in a dish are at a lower temperature than the surrounding air and objects in the room.
2. Heat is transferred from the warmer surroundings to the cooler ice cubes by radiation and conduction.
3. As the ice cubes absorb this heat from the surroundings, they melt into water.

**Answer:** The ice cubes get heat from the warmer surroundings and the dish through radiation and conduction.

> Common mistake: Assuming ice cubes generate their own heat or melt without taking heat from the surroundings.

### Question 5

*3 marks · Short answer*

A burning incense stick is fixed, pointing downwards. In which direction would the smoke from the incense stick move? Show the movement of smoke with a diagram.

**Solution**

1. When an incense stick is burnt, the hot gases and smoke produced are warmer than the surrounding air.
2. Since warm air and gases are lighter, they rise upwards due to convection, regardless of the orientation of the incense stick.
3. Diagram: Draw an incense stick pointing downwards with arrows showing the smoke curling up and moving vertically upwards.

**Answer:** The smoke from the incense stick will move upwards because hot air and gases are lighter and rise.

> Common mistake: Thinking the smoke will follow the direction in which the stick is pointing.

### Question 6

*3 marks · Short answer*

Two test tubes with water are heated by a candle flame as shown in Fig. 7.16. Which thermometers (Fig. 7.16a or Fig. 7.16b) will record a higher temperature? Explain.

**Solution**

1. The thermometer in Fig. 7.16(b) will record a higher temperature.
2. In Fig. 7.16(b), the candle is placed directly below the bottom of the test tube, causing the water near the base to heat up, expand, and rise through convection.
3. In Fig. 7.16(a), the candle is at the side near the top, and convection currents do not heat the lower region where the thermometer bulb is placed as effectively.

**Answer:** Thermometer in Fig. 7.16(b) will record a higher temperature because heating water from the bottom sets up convection currents that quickly heat the entire liquid.

> Common mistake: Not considering the direction of convection currents in liquids.

### Question 7

*3 marks · Short answer*

Why are hollow bricks used to construct the outer walls of houses in hot regions?

**Solution**

1. Hollow bricks have air trapped inside their cavities.
2. Air is a poor conductor (insulator) of heat.
3. This trapped layer of air prevents outside heat from entering the houses during summers, keeping the interiors cool.

**Answer:** Hollow bricks trap air which acts as a poor conductor of heat and prevents outside heat from entering houses in hot regions.

> Common mistake: Stating that hollow bricks let heat pass through easily.

### Question 8

*3 marks · Short answer*

Explain how large water bodies prevent extreme temperature in areas around them.

**Solution**

1. Large water bodies like seas and oceans heat up and cool down slower than land.
2. During the day, land gets heated faster than water, causing cooler air to move from the sea to the land as sea breeze.
3. At night, land cools down faster than water, causing cooler air to move from the land to the sea as land breeze, preventing extreme temperatures.

**Answer:** Large water bodies prevent extreme temperatures through the formation of sea and land breezes due to the different rates of heating and cooling of land and water.

> Common mistake: Stating that land and water heat up and cool down at the same rate.

### Question 9

*3 marks · Short answer*

Explain how water seeps through the surface of the Earth and gets stored as groundwater.

**Solution**

1. Surface water seeps through the spaces between soil particles and rocks in a process called infiltration.
2. Water seeps faster through materials with wider, open, and interconnected spaces like gravel compared to clay.
3. The water that seeps through gets stored in the pore spaces of sediments and rocks beneath the surface to form groundwater and aquifers.

**Answer:** Surface water seeps into the ground through infiltration, moving through soil and rock particles, and gets stored in underground layers called aquifers as groundwater.

> Common mistake: Confusing infiltration with precipitation.

### Question 10

*3 marks · Short answer*

The water cycle helps in the redistribution and replenishment of water on the Earth. Justify the statement.

**Solution**

1. Water from oceans, rivers, and lakes gets heated by the Sun and evaporates into water vapour, while plants release water through transpiration.
2. Water vapour rises, cools, and condenses to form clouds, which bring rain, snow, and hail through precipitation.
3. The continuous upward movement as water vapour and downward movement through precipitation returns water to water bodies, thus redistributing and replenishing it.

**Answer:** The water cycle redistributes and replenishes water on Earth through the continuous cycle of evaporation, transpiration, condensation, and precipitation.

> Common mistake: Omitting transpiration or the role of the Sun in evaporation.

## Frequently asked questions

### How many questions are there in NCERT Solutions for Class 7 Science Chapter 7 Heat Transfer in Nature?

There are 15 questions in the Let Us Enhance Our Learning section of this chapter. You can find step-by-step solutions for all of them in the free PDF available on this SwaVid page.

### Which topics are covered in the exercises of Class 7 Science Chapter 7?

The exercise questions cover important concepts like conduction in metal strips, conductors and insulators of heat, air as a poor conductor, convection currents in air and water, heat transfer in solids, and insulation by trapped air in hollow bricks. SwaVid provides detailed explanations for each of these topics on this page.

### What are the types of questions asked in the new NCERT book for Class 7 Science Chapter 7?

The exercises include multiple-choice questions (MCQs), short answer questions, and true or false statements as per the new NCERT book for the 2026-27 session. You can access the complete solutions for all these question types in the free PDF on this SwaVid page.

### How should I write answers to score full marks in Class 7 Science Chapter 7 Heat Transfer in Nature?

To score full marks, structure your answers clearly by defining key scientific terms and explaining the direction of heat transfer using principles like conduction and convection. Referring to the solved examples in the free PDF on this SwaVid page will help you understand the ideal answer format.

### Is the free PDF for Class 7 Science Chapter 7 Heat Transfer in Nature available here?

Yes, the complete chapter solutions aligned with the new NCERT book for the 2026-27 session are available as a free PDF. You can download and view the step-by-step answers directly from this SwaVid page.

## Related pages

- [Class 7 Science chapters](https://www.swavid.com/science/class/7)

Solutions written by SwaVid, a personal AI tutor for Class 6 to 10 Maths and Science. Practise this chapter free: https://www.swavid.com/start/student