Table of Contents
Chapter 3 – Heat – Worksheets
These worksheets are designed to accompany the chapter on “Heat.” This chapter covers how heat is produced, transferred, and measured. Students will explore different concepts of heat in everyday life. The worksheets include both solved and unsolved versions for effective learning.
Key concepts covered in the chapter and explored through these worksheets include:
- Understanding Heat: Learning about the nature of heat and how it affects different materials.
- Measuring Temperature: Exploring how temperature is measured using different types of thermometers.
- Heat Transfer: Studying how heat moves from one object to another through conduction, convection, and radiation.
The solved worksheets provide methods and solutions for the topics, while the unsolved worksheets allow students to practise and self-assess their understanding.
Also Check – Rapid Revision – Class 7 Science -Chapter 3 – Heat– Complete Notes
Worksheet 1 – Heat – Student Worksheet (Unsolved)
Question – Explain the process of convection and how it applies to heat transfer in water and air. Provide an example.
Question – Discuss the concept of conductors and insulators of heat. Provide examples and explain how this concept is applied in everyday life.
Question – Describe the phenomenon of sea breeze and land breeze, explaining the role of differential heating in these processes.
Question – Explain why dark-coloured surfaces retain heat for longer periods compared to light-coloured surfaces and how this concept applies to clothing choices in different seasons.
Question – Complete the following sentences:
(a) In a convection experiment with water, the movement of heated water demonstrates __________.
(b) The ability of metals like __________, __________, and __________ to conduct heat makes them ideal for cooking utensils.
(c) Houses in coastal areas often have windows facing the sea to take advantage of the __________ during the day.
(d) The __________ feels hotter than the hand on the side of a candle flame due to the upward flow of hot air.
Question – Identify the following:
(i) A good conductor of heat commonly used in cookware.
(ii) An insulating material used in the handles of cooking utensils.
(iii) A natural process that causes the sea breeze.
Question – Choose the correct answer:
(a) What is the primary reason for the effectiveness of light-coloured clothes in summer?
(i) They absorb more heat.
(ii) They reflect sunlight.
(b) Why do dark-coloured clothes help in staying warm in winter?
(i) They reflect sunlight.
(ii) They absorb more heat.
Question – Match the following:
| Column I | Column II |
| Convection | Heat transfer by fluid movement |
| Conductors | Allow heat to pass through easily |
| Insulators | Do not allow heat to pass through easily |
| Sea Breeze | Cool air from the sea replacing hot air over land |
Question – True or False Statements:
(i) Convection is a significant mode of heat transfer in both liquids and gases. (T/F)
(ii) Light-coloured surfaces absorb heat more efficiently than dark-coloured surfaces. (T/F)
(iii) Land breeze occurs at night due to the land cooling down more slowly than water. (T/F)
(iv) Metals are poor conductors of heat. (T/F)
Question – Discuss how the colour of clothing affects body temperature regulation in different seasons.
Also Check – Class 7 science -Chapter 4 – Heat -Detailed Notes
Worksheet 1 – Heat – Solved Worksheet
Question – Explain the process of convection and how it applies to heat transfer in water and air. Provide an example.
Answer- Convection is the transfer of heat through the movement of fluids (liquids and gases). It occurs when heated particles of a fluid move from one place to another, transferring heat. For example, in boiling water, the water at the bottom heats up first and rises, while cooler water moves down to replace it, creating a convection current.
Question – Discuss the concept of conductors and insulators of heat. Provide examples and explain how this concept is applied in everyday life.
Answer- Conductors of heat, like metals (aluminium, iron, copper), allow heat to flow through them easily. Insulators like plastic and wood do not allow heat to flow through them easily. This concept is applied in everyday life in the use of cooking utensils made of metals and insulating materials for their handles to prevent burns.
Question – Describe the phenomenon of sea breeze and land breeze, explaining the role of differential heating in these processes.
Answer-The sea breeze occurs during the day when the land heats up faster than the sea, causing the air over the land to rise and cooler air from the sea to move in. At night, the process reverses, and the land cools down more quickly than the water, so cooler air from the land moves towards the sea, creating a land breeze.
Question – Explain why dark-coloured surfaces retain heat for longer periods compared to light-coloured surfaces and how this concept applies to clothing choices in different seasons.
Answer-Dark-coloured surfaces absorb more sunlight and retain heat for longer periods than light-coloured surfaces, which reflect most of the sunlight. Therefore, in summer, light-coloured clothes keep us cooler, and in winter, dark-coloured clothes help retain body heat.
Question – Complete the following sentences:
Answer-(a) Convection currents
(b) Aluminium, iron, copper
(c) Sea breeze
(d) Hand above
Question – Identify the following:
Answer-(i) Copper
(ii) Plastic or wood
(iii) Differential heating of land and sea
Choose the correct answer:
(a) (ii) They reflect sunlight.
(b) (ii) They absorb more heat.
Question – Match the following:
Answer-
- Convection: Heat transfer by fluid movement
- Conductors: Allow heat to pass through easily
- Insulators: Do not allow heat to pass through easily
- Sea Breeze: Cool air from the sea replacing hot air over land
Question – True or False Statements:
Answer-
(i) T
(ii) F
(iii) T
(iv) F
Question – Discuss how the colour of clothing affects body temperature regulation in different seasons.
Answer-In summer, light-coloured clothing is preferred because it reflects sunlight and heat, keeping the body cooler. In contrast, dark-coloured clothing is better in winter because it absorbs more sunlight and heat, helping to keep the body warmer.
Also Check – Class 7 science -Chapter 4 – Heat – Definition and Explanation of Important Keywords
Worksheet 2 – Heat – Student Worksheet (Unsolved)
Question – Explain how exhaust fans in kitchens and room heaters utilise the concept of convection for temperature regulation.
Question – Describe the design and function of a thermos flask, explaining how it utilises the concepts of conduction, convection, and radiation to maintain the temperature of liquids.
Question – Discuss the practical applications of radiation in everyday life, such as in solar heaters.
Question – Explain why light-coloured clothes are preferred in summer and dark-coloured clothes in winter.
Question – Describe the process of heat transfer in solids, known as conduction, and give examples of good conductors of heat.
Question – Fill in the blanks:
(a) The process of __________ involves the transfer of heat through the movement of fluids.
(b) In the process of __________, heat is transferred in the form of rays without requiring a medium.
(c) __________ are effective in maintaining the temperature of liquids by preventing heat loss through conduction, convection, and radiation.
(d) __________ utilises the sun’s heat for practical applications like cooking.
Question – Identify the following:
(i) A device that helps to maintain room temperature by circulating air.
(ii) A material that is a good conductor of heat, often used in cookware.
(iii) A material that acts as an insulator, used in the outer casing of a thermos flask.
Question – Choose the correct answer:
(a) What is the primary reason for placing room heaters on the floor?
(i) To heat the air at the top of the room first.
(ii) To allow warm air to rise and circulate.
(b) Why are solar heaters an effective way to utilise natural energy?
(i) They conduct heat from the ground.
- (ii) They use radiation from the sun.
Question – Match the following:
| Column I | Column II |
| Conduction | Heat transfer in solids |
| Convection | Heat transfer by fluid movement |
| Radiation | Heat transfer through vacuum |
| Thermos Flask | Maintains liquid temperature |
Question – True or False Statements:
(i) Convection is the primary method of heat transfer in gases. (T/F)
(ii) Radiation can occur only in the presence of a medium. (T/F)
(iii) A thermos flask prevents heat loss mainly through conduction. (T/F)
- (iv) Wearing dark-coloured clothes in winter helps in absorbing more heat. (T/F)
- Discuss the advantages of using solar heaters in terms of energy efficiency and environmental impact.
Also Check -Chapter 3 Heat Activities: Simple Experiments for Class 7
Worksheet 2 – Heat – Solved Worksheet
Question –Explain how exhaust fans in kitchens and room heaters utilise the concept of convection for temperature regulation.
Answer-Exhaust fans in kitchens are fitted high up because hot air rises. They remove the hot air efficiently. Room heaters are placed on the floor; as the air near them gets heated, it rises, and the cooler air moves down to be heated, effectively warming the entire room through convection.
Question –Describe the design and function of a thermos flask, explaining how it utilises the concepts of conduction, convection, and radiation to maintain the temperature of liquids.
Answer-A thermos flask has a double-walled container, usually made of glass or stainless steel, with a vacuum between the walls. This vacuum prevents heat loss through convection. The walls are polished, making them shiny to reflect heat and reduce heat loss through radiation. The outer casing, often made of plastic, acts as an insulator to minimise heat loss through conduction.
Question –Discuss the practical applications of radiation in everyday life, such as in solar heaters.
Answer-Solar heaters use the concept of radiation to absorb heat energy from the sun for cooking food. Radiation allows transfer of heat energy in the form of rays, which can travel through a vacuum, such as the space between the Sun and the Earth.
Question –Explain why light-coloured clothes are preferred in summer and dark-coloured clothes in winter.
Answer-Light-coloured clothes are preferred in summer as they absorb less heat from the sun, keeping the body cooler. Conversely, dark-coloured clothes are better in winter as they absorb more heat, keeping the body warmer.
Question –Describe the process of heat transfer in solids, known as conduction, and give examples of good conductors of heat.
Answer-Conduction is the process where heat is transferred through a material, typically a solid, without the material itself moving. Good conductors of heat include metals such as iron, copper, and aluminium.
Question –Fill in the blanks:
Answer-
(a) Convection
(b) Radiation
(c) Thermos flasks
(d) Solar heaters
Question –Identify the following:
Answer-
(i) Exhaust fan
(ii) Copper
(iii) Plastic
Question –Choose the correct answer:
Answer-
(a) (ii) To allow warm air to rise and circulate.
(b) (ii) They use radiation from the sun.
Question –Match the following:
Answer-
- Conduction: Heat transfer in solids
- Convection: Heat transfer by fluid movement
- Radiation: Heat transfer through vacuum
- Thermos Flask: Maintains liquid temperature
Question –True or False Statements:
Answer-
(i) T
(ii) F
(iii) F
(iv) T
Question –Discuss the advantages of using solar heaters in terms of energy efficiency and environmental impact.
Answer-Solar heaters are energy-efficient as they utilise the abundant and renewable energy from the sun. They reduce reliance on fossil fuels, minimising carbon emissions and environmental impact. Solar heaters are cost-effective in the long run and contribute to sustainable living.
Also Check – NCERT Solutions For Class 7 Science Chapter 4 – Heat
Worksheet 3 – Heat – Student Worksheet (Unsolved)
Question –Explain why the air above the land gets heated faster than the air above the sea and how this results in sea breeze.
Question –Describe why land breeze occurs at night and the process that leads to it.
Question –Explain the significance of wearing light-coloured clothes in summer and dark-coloured clothes in winter.
Question –Discuss how woollen clothes help in keeping us warm during winters.
Question –Define conduction and give two examples of good conductors of heat.
Question –Complete the following sentences:
(a) Radiation is a process of heat transfer that involves ________________.
(b) ________________ is the process where heat is transferred in liquids and gases.
(c) Sea breeze typically occurs during the ________________ due to differential heating of land and sea.
(d) The thermometer used for measuring human body temperature is called a ________________ thermometer.
Question –Identify the following:
(i) A device used to measure the minimum and maximum temperatures of the day.
(ii) An example of an insulator of heat.
(iii) The part of the human body where clinical thermometers are usually placed for temperature reading.
Question –Choose the correct answer:
(a) Which process explains why the top layer of water in a pond is warmer on a sunny day?
(i) Conduction (ii) Convection (iii) Radiation (iv) Insulation
(b) What is typically used in weather forecasting to measure temperature variations throughout the day?
(i) Clinical thermometer (ii) Laboratory thermometer (iii) Minimum-maximum thermometer (iv) Digital thermometer
Question –Match the following:
| Column I | Column II |
| Conduction | Direct transfer of heat through a substance |
| Convection | Transfer of heat in fluids |
| Radiation | Transfer of heat in the form of waves |
| Thermometer | Device used to measure temperature |
Question –True or False Statements:
(i) Insulators can be used to prevent the loss of heat from objects. (T/F)
(ii) Digital thermometers are less accurate than mercury thermometers. (T/F)
(iii) Dark-coloured clothes absorb more heat compared to light-coloured clothes. (T/F)
(iv) Two thin blankets are warmer than one thick blanket because of the trapped air. (T/F)
Question –Choose the correct answer:
During summer, it is advised to paint the outer walls of houses white because white colour:
(i) Absorbs all colours (ii) Reflects all colours (iii) Absorbs heat (iv) None of the above
Question –Multiple-choice question:
In which of the following scenarios will convection most likely occur?
(i) Heating of a metal rod from one end (ii) Boiling water in a pot (iii) Heating a room with a radiator (iv) Sun warming the Earth
Question –Explain how a digital thermometer works and its advantages over traditional mercury thermometers.
Also Check – Sea Breezes and Land Breezes – Class 7 Science explained in details
Worksheet 3- Heat – Solved Worksheet
Question – Explain why the air above the land gets heated faster than the air above the sea and how this results in sea breeze.
Answer-The air above the land heats up faster than the air above the sea due to the sun’s radiation. Land absorbs and radiates heat quicker than water. This causes the air over land to heat up and rise, creating a lower pressure area. Cooler, denser air from the sea moves in to replace it, creating a sea breeze.
Question – Describe why land breeze occurs at night and the process that leads to it.
Answer-At night, the land cools down faster than the sea. The air above the sea is warmer and rises, creating a lower pressure area. Cooler air from the land then moves towards the sea to replace it, resulting in a land breeze.
Question – Explain the significance of wearing light-coloured clothes in summer and dark-coloured clothes in winter.
Answer-Light-coloured clothes reflect more of the sun’s heat, keeping us cooler in summer. In contrast, dark-coloured clothes absorb more heat, keeping us warmer in winter.
Question – Discuss how woollen clothes help in keeping us warm during winters.
Answer-Woollen clothes are poor conductors of heat and have air trapped between their fibres. This air acts as an insulator, preventing body heat from escaping, thus keeping us warm.
Question – Define conduction and give two examples of good conductors of heat.
Answer-Conduction is the transfer of heat through a material without the movement of the material itself. Good conductors of heat include metals like copper and aluminium.
Question – Complete the following sentences:
Answer-(a) electromagnetic waves
(b) Convection
(c) day
(d) clinical
Question – Identify the following:
Answer-(i) Minimum-maximum thermometer
(ii) Wood
(iii) Mouth
Question – Choose the correct answer:
Answer-(a) (ii) Convection
(b) (iii) Minimum-maximum thermometer
Question – Match the following:
Answer-
- Conduction: Direct transfer of heat through a substance
- Convection: Transfer of heat in fluids
- Radiation: Transfer of heat in the form of waves
- Thermometer: Device used to measure temperature
Question – True or False Statements:
Answer-
(i) T
(ii) F
(iii) T
(iv) T
Question – Choose the correct answer:
Answer-During summer, it is advised to paint the outer walls of houses white because white colour:
(ii) Reflects all colours
Question – Multiple-choice question:
In which of the following scenarios will convection most likely occur?
Answer-(ii) Boiling water in a pot
Question – Explain how a digital thermometer works and its advantages over traditional mercury thermometers.
Answer-Digital thermometers use electronic heat sensors to record body temperature. They display readings on a digital screen. Advantages over mercury thermometers include safety (no risk of mercury poisoning), ease of reading, faster and more accurate readings, and they can be used to measure temperature in different ways (oral, rectal, underarm).
Also Check – Difference Between Sea Breeze And Land Breeze
Worksheet 4 – Heat – Student Worksheet (Unsolved)
Question –Explain the concept of temperature and how it is measured with a thermometer.
Question –Describe the features and uses of a clinical thermometer.
Question –Outline the steps and precautions for reading a clinical thermometer.
Question –Discuss the design and range of a laboratory thermometer and how it is different from a clinical thermometer.
Question –Explain the concept of conduction and give examples of conductors and insulators of heat.
Question –Complete the following sentences:
(a) When two objects at different temperatures come in contact, heat flows from the ______________ object to the ______________ object.
(b) ______________ is the transfer of heat in fluids by the movement of the fluid itself.
(c) ______________ is the mode of heat transfer through empty space or vacuum.
(d) During the day, ______________ blows from the sea to the land due to differential heating.
Question –Choose the correct answer:
(a) Why are woollen clothes warm in winter?
(i) They are good conductors of heat.
(ii) They trap air, which is a poor conductor of heat.
(b) Which process of heat transfer is primarily responsible for sea and land breezes?
(i) Conduction (ii) Convection (iii) Radiation
Question –Match the following:
| Column I | Column II |
| Conduction | Transfer of heat in solids |
| Convection | Transfer of heat in fluids |
| Radiation | Transfer of heat through vacuum |
| Clinical Thermometer | Used for measuring body temperature |
Question –True or False Statements:
(i) A laboratory thermometer can be used to measure human body temperature. (T/F)
(ii) Dark-coloured clothes absorb more heat compared to light-coloured clothes. (T/F)
(iii) Radiation requires a medium for heat transfer. (T/F)
(iv) Convection occurs only in liquids and gases. (T/F)
Question –Discuss why light-coloured clothes are preferred in summer and dark-coloured clothes in winter.
Also Check – Conduction, Convection, and Radiation- Class 7 Science Explained
Worksheet 4- Heat – Solved Worksheet
Question –Explain the concept of temperature and how it is measured with a thermometer.
Answer-Temperature is the degree of hotness or coldness of an object. It’s measured using a thermometer, an instrument with a scale marked on it used to read the temperature. Thermometers typically contain a liquid like mercury that expands or contracts with temperature changes.
Question –Describe the features and uses of a clinical thermometer.
Answer-A clinical thermometer is used to measure human body temperature, typically ranging from 35°C to 42°C. It consists of a long glass tube with a thin, uniform bore and a mercury-filled bulb. A kink in the tube prevents mercury from falling back, allowing for accurate temperature readings.
Question –Outline the steps and precautions for reading a clinical thermometer.
Answer-Steps: Wash with antiseptic, ensure mercury is below 35°C, place under the tongue for a minute, read the temperature.
Precautions: Use antiseptic, ensure correct mercury level, read while the thermometer is horizontal, don’t hold by the bulb, handle carefully.
Question –Discuss the design and range of a laboratory thermometer and how it is different from a clinical thermometer.
Answer-A laboratory thermometer measures temperatures from -10°C to 110°C. It has a long glass tube with a thin bore and is used for various scientific measurements, unlike the clinical thermometer which is specifically for body temperature.
Question –Explain the concept of conduction and give examples of conductors and insulators of heat.
Answer-Conduction is the transfer of heat through a material without the movement of the material itself. Conductors like iron, copper, and aluminium allow heat to pass through easily, while insulators like wood and plastic do not.
Question –Complete the following sentences:
Answer-(a) hotter; colder
(b) Convection
(c) Radiation
(d) Sea breeze
Question –Choose the correct answer:
Answer-(a) (ii) They trap air, which is a poor conductor of heat.
(b) (ii) Convection
Question –Match the following:
Answer-
- Conduction: Transfer of heat in solids
- Convection: Transfer of heat in fluids
- Radiation: Transfer of heat through vacuum
- Clinical Thermometer: Used for measuring body temperature
Question –True or False Statements:
Answer-
(i) F
(ii) T
(iii) F
(iv) T
Question –Discuss why light-coloured clothes are preferred in summer and dark-coloured clothes in winter.
Answer-Light-coloured clothes reflect more heat, keeping the body cooler in summer. Dark-coloured clothes absorb more heat, keeping the body warmer in winter.
Also Check – NCERT Exemplar Solutions- Class 7 Science – Chapter 3 – Heat
Worksheet 5 – Heat – Student Worksheet (Unsolved)
Question –Explain how the sensation of warm or cold is felt and what factors influence it.
Question –Describe the construction and functioning of a clinical thermometer.
Question –Outline the correct procedure for reading a clinical thermometer, including safety precautions.
Question –Discuss the characteristics and usage of a laboratory thermometer and how it differs from a clinical thermometer.
Question –Explain the process of heat transfer, focusing on the flow of heat from hot to cold objects.
Question –Fill in the blanks:
(a) When touching different materials at the same temperature, they may feel differently due to their ____________ as heat conductors.
(b) Heat transfer by ____________ occurs in liquids and gases due to the movement of the fluid.
(c) The process of ____________ allows heat transfer in a vacuum, as experienced from the sun’s heat reaching Earth.
Question –Describe the role of clothing in regulating body temperature during different seasons.
Question –Explain the concept of conduction and how different materials conduct heat. Provide examples of good and bad conductors.
Question –Discuss how woollen clothes and layered clothing help to keep us warm in winter.
Question –Explain why light-coloured clothes are preferred in summer, while dark-coloured clothes are chosen in winter.
Worksheet 5- Heat – Solved Worksheet
Question –Explain how the sensation of warm or cold is felt and what factors influence it.
Answer-The sensation of warmth or cold is felt through our sense of touch. We perceive an object’s temperature by touching it. However, this perception can be misleading as it depends on the object’s ability to conduct heat. Some materials conduct heat away from our hands faster than others, making them feel colder, even if they are at the same temperature.
Question –Describe the construction and functioning of a clinical thermometer.
Answer-A clinical thermometer consists of a long, narrow glass tube with a mercury-filled bulb at one end. It has a kink near the bulb to prevent mercury from falling back, allowing for accurate temperature readings. Mercury in the bulb expands and rises up the tube when exposed to higher temperatures, indicating the temperature on a marked scale.
Question –Outline the correct procedure for reading a clinical thermometer, including safety precautions.
Answer-
- Wash the thermometer, preferably with antiseptic.
- Ensure mercury is below 35°C before use.
- Place the bulb under the patient’s tongue for a minute.
- Read the temperature by aligning the top of the mercury column with your line of sight.
- Handle the thermometer carefully to avoid breakage.
- Do not hold the thermometer by the bulb while reading.
Question –Discuss the characteristics and usage of a laboratory thermometer and how it differs from a clinical thermometer.
Answer-A laboratory thermometer measures a wide range of temperatures, from -10°C to 110°C. It’s designed for scientific measurements in various substances, not for body temperature. Unlike clinical thermometers, the mercury in laboratory thermometers can quickly fall once removed from the substance being measured.
Question –Explain the process of heat transfer, focusing on the flow of heat from hot to cold objects.
Answer-Heat transfer is the process where heat flows from a hotter object to a colder one until they reach thermal equilibrium. This transfer occurs through conduction in solids, convection in fluids, and radiation in vacuum or space.
Question –Fill in the blanks:
Answer-(a) conductivity
(b) Convection
(c) Radiation
Question –Describe the role of clothing in regulating body temperature during different seasons.
Answer-Clothing plays a vital role in body temperature regulation. In summer, light-coloured clothes reflect heat, keeping the body cool. In winter, dark-coloured clothes absorb heat, and woollen clothes trap air, which acts as an insulator, keeping the body warm.
Question –Explain the concept of conduction and how different materials conduct heat. Provide examples of good and bad conductors.
Answer-Conduction is the transfer of heat through a material without the material moving as a whole. Good conductors, like metals (iron, copper, aluminium), allow heat to pass through easily. Bad conductors or insulators, such as wood, plastic, and glass, do not conduct heat efficiently.
Question –Discuss how woollen clothes and layered clothing help to keep us warm in winter.
Answer-Woollen clothes and layered clothing trap air between fibres and layers. Air, being a poor conductor of heat, prevents body heat from escaping, keeping us warm in winter.
Question –Explain why light-coloured clothes are preferred in summer, while dark-coloured clothes are chosen in winter.
Answer-Light-coloured clothes reflect most of the sunlight, keeping the body cool in summer. Dark-coloured clothes absorb more sunlight and retain heat, making them preferable in winter to stay warm.
