Important Questions for CBSE Class 7 Science Chapter 3 - Heat

Very Short Answer Questions:

Q1. Hotness of an object is measured using ___________. 

Ans: The hotness of an object is measured using a thermometer. 

Q2. ____________ is the reliable measure of hotness. 

Ans: Temperature is a reliable measure of hotness. 

Q3. The thermometer shown in the figure is ______________.

Clinical Thermometer

Ans: The thermometer shown in the figure is  clinical.

Clinical thermometers are devices that are used to measure the temperature of a human body.

4. Thermometer shown in the diagram is _______________.

Thermometer

Ans: The thermometer shown in the diagram is laboratory.

A laboratory thermometer is a device that is used to measure temperatures in schools or other laboratories for scientific purposes.

5. The red colour shows ____________ temperature and the blue colour shows_________ temperature.

Given picture of Thermometer

Ans: The red color shows maximum temperature and the blue color shows minimum temperature.

Q6. India has adopted the _______ scale for temperature measurement. 

Ans: India has adopted the Celsius scale for temperature measurement. 

Q7. The scale used to measure temperature earlier was the _________________ scale. 

Ans: The scale used to measure temperature earlier was the Fahrenheit scale. 

Q8. The normal body temperature of the human body is _______. 

Ans: The normal body temperature of the human body is 37oC.

Q9. The _____________in the clinical thermometer prevents the mercury from falling on its own. 

Ans: The kink in the clinical thermometer prevents the mercury from falling on its own. 

Q10. The human body temperature does not rise above ________________.

Ans: The human body temperature does not rise above 42oC.

Short Answer Questions:

Q1. What is conduction?

Ans: Conduction is the direct movement of heat from one point of an object to another by direct contact. Heat is transferred between materials that are in direct touch with one another. The heated object will transfer heat to every nearby object that comes into direct contact with it, and this process will continue as long as there are objects in contact. It is the most often used mode of transfer of heat in objects.

Phenomenon of Conduction

Q2. What is convection?

Ans: Convection is a heat transport method that occurs in liquids and gases. The fluid is heated unevenly in this manner. A portion of the fluid heats up, expands, and rises. Colder fluids rush in from the surrounding locations to fill the void left by the rising hot fluid. They are heated one by one, and the process is continued until the entire fluid is heated. Winds and storms are caused by the process of convection.

Phenomenon of Convection

Q3. What is radiation?

Ans: Radiation is the transfer of heat between objects that are not in direct touch. The two items may be solids or liquids, but they are not in contact. Heat is transferred from a distance when a heated object radiates heat into the environment. There is no need for a medium for radiation. Because it emits heat to the surroundings, a hot object cools down on its own.

Phenomenon of Radiation

Q4. What are insulators?

Ans: Insulators are poor heat-conducting materials. These materials make it difficult for heat to pass through them. As a result, insulators are utilized to construct handles for cooking pots and pans so that we may grasp them without getting burned. Insulators include materials such as plastic, wood, and rubber.

Q5. What are conductors?

Ans: The materials that conduct heat are called conductors. Heat easily passes through these materials. Cooking utensils, for example, are made with conductors to ensure that the heat from the flame is quickly transferred to the food. Conductors can be made of aluminum, iron, or copper.

Long Answer Questions:  

Q1. What is a sea breeze?

Ans: A sea breeze is a local wind system that flows from the sea to land during the day. This is a common occurrence along the coast. The land heats up faster than the sea during the day. As a result, the air above the ground warms, expands, and rises. The cooler air from the sea rushes in to fill the void that has been created. The air from the land is moving towards the sea. The sea breeze is the wind that blows from the sea towards the land during the day. Houses in coastal areas are built with windows that face the sea to capture the most amount of sea breeze. In the absence of a strong large-scale wind system, sea breezes alternate with land breezes along the coasts of oceans or large lakes during periods of intense daytime heating or nighttime cooling.

Sea Breeze

Q2. What is a land breeze?

Ans: Land breeze refers to the breeze that blows from the land towards the sea at night. They form at night when both seawater and land lose heat. Because the specific heat capacity of the land is much lower than that of seawater, the land loses heat energy quickly and cools faster than the sea. This is a common occurrence along the coast. The land cools much faster than the seawater at night. As a result, the air above the land cools off more quickly. Above the sea, the air remains warm, expands, and rises. Air from the ground rushes in to fill the void

Land Breeze

Q3. How does wearing woolen clothes keep us warm in winters?

Ans: Woollen clothing is good for the winter since it keeps us warm. This is because-

1. Wool conducts heat poorly, it does not conduct body heat.

2. Air trapped between the pores of woolen fibers is a poor heat conductor.

This also reduces the transfer of heat from the body to the environment.

We feel warm because our body heat is trapped within the layers of clothes. Also, having many layers of clothing is preferable to wearing a single thick woolen fabric. This is due to the fact that air is trapped between each layer, trapping more heat. As a result, we feel more comfortable.

Download Important Questions for Class 7 Science Chapter 3 PDF

Class 7 Science Chapter 3 Heat Summary

Hot and Cold - In this topic, we will learn the effects of heat energy on different materials with practical activities. This will help us to understand the concept in a better way. In our day-to-day life, we have come across many hot and cold objects. For example, tea is hot and ice is cold. The thermometer is a device to measure the temperature of any object or body, mainly we use a thermometer to measure our body temperature.

Measuring Temperature - Measurement of temperature is very important in our day-to-day life. As we know, Doctors use the thermometer to measure body temperature, it is also known as a clinical thermometer. It is long and narrow, made of a uniform glass tube with a bulb at one end. And that bulb contains mercury, which is the main source of measurement in the thermometer. There are two types of scale found on thermometers: one is the Celsius scale and the other is the Fahrenheit scale. Different types of thermometers have different applications like maximum and the minimum thermometer is used for the weather analysis and clinical thermometer is used to measure human body temperature.

Clothes we wear in Summer and Winter - During the summer season, we usually prefer to wear light coloured clothes and in winter we wear dark coloured clothes. The main reason behind it is dark coloured clothes absorb more heat during winter, so we feel more comfortable wearing dark coloured clothes. In vise-versa if we wear light coloured clothes in summer we feel more comfortable as it absorbs less heat most of the light falling on them gets reflected. And we wear woollen clothes during winter as we know, Woolen clothes are a bad conductor of heat.

Transfer of Heat - This will help the student to understand different heat transfers occurring in our surroundings such as frying pan becomes hot when kept on the flame. And it slowly cools down, when the pan is removed from the flame. This happens because heat is a form of energy that spontaneously transfers from hotter objects to cooler objects known as conduction. The materials which allow the heat to pass through them are known as conductors. And the materials through which heat does not pass through it are known as insulators.

Advantages of Practising Important Questions for CBSE Class 7 Science Chapter 3 - Heat

Practicing important questions for CBSE Class 7 Science Chapter 3 - Heat offers several advantages for students, facilitating a comprehensive understanding of the topic. Some of the key benefits include:

• Focus on Exam Relevance: Important questions are curated to align with the CBSE examination pattern, enabling students to concentrate on topics that are likely to be asked in the exams.

• Thorough Conceptual Clarity: By attempting these questions, students gain a deeper comprehension of the fundamental concepts related to heat, such as thermal expansion, heat transfer, and specific heat.

• Application of Knowledge: Important questions often involve problem-solving scenarios, encouraging students to apply their knowledge to real-life situations, thus enhancing their critical thinking abilities.

• Time Management: Practicing these questions helps students improve their time management skills as they learn to answer questions within the allocated time frame.

• Revision Efficiency: Repeatedly practicing important questions aids in efficient revision, ensuring that students retain the information effectively.

• Self-Assessment: By attempting these questions, students can self-assess their level of preparation and identify areas that require further improvement.

• Confidence Building: As students solve a wide range of questions, they gain confidence in their ability to tackle different question types and complexities.

• Test Preparation: Important questions mimic the examination style, enabling students to feel more prepared and less anxious about the actual test.

• Comprehensive Coverage: These questions cover various aspects of the chapter, ensuring that students have a holistic understanding of the topic.

• Reinforcement of Learning: Regular practice of important questions reinforces the concepts learned in class, helping students solidify their knowledge.

Conclusion

By going through all Class 7 Science Chapter 3 important questions, students will get a clear understanding of the topics covered in the chapter. Class 7 Science Chapter 3 extra questions and important questions cover all the topics given in this chapter in a concept-based discussion. This question and answer approach can save a lot of time for students during their exam preparation as it becomes easier to revise the chapter by practising these important questions.