CBSE Important Questions for Class 6 Science Temperature and its Measurement - 2025-26

1. What is temperature?
Temperature is a measure of how hot or cold something is. It indicates the average energy of the particles in a substance. Higher temperatures mean that the particles move faster, while lower temperatures indicate slower-moving particles. In everyday life, we use temperature to describe the warmth of the air, liquids, and objects.

2. Why is temperature important in daily life?
Temperature affects many aspects of our daily lives, including weather conditions, cooking, and health. For example, knowing the temperature helps us decide how to dress for the day, ensures food is cooked properly to avoid illness, and allows us to monitor body temperature to check for fevers.

3. What are the units of temperature?
The most common units of temperature are degrees Celsius (°C), degrees Fahrenheit (°F), and Kelvin (K). Degrees Celsius is widely used in most countries for everyday temperature measurements. Degrees Fahrenheit is mainly used in the United States. The Kelvin scale is used in scientific contexts, especially in physics and chemistry.

4. How do you convert Celsius to Fahrenheit?
To convert Celsius to Fahrenheit, use the formula:
$°F = (°C \times \frac{9}{5}) + 32$

For example, to convert 25°C to Fahrenheit:
$°F = (25 \times \frac{9}{5}) + 32 = 77°F$
This formula helps you understand how temperatures relate between the two scales.

5. How do you convert Fahrenheit to Celsius?
To convert Fahrenheit to Celsius, use the formula:
$C = (°F - 32) \times \frac{5}{9}$​
For instance, to convert 68°F to Celsius:
$°C = (68 - 32) \times \frac{5}{9} = 20°C$
This formula allows you to switch between the two temperature scales effectively.

6. What instrument is used to measure temperature?
A thermometer is an instrument used to measure temperature. There are various types, including liquid-in-glass thermometers, digital thermometers, and infrared thermometers. Each type works differently, but they all provide a way to measure how hot or cold something is accurately.

7. How does a liquid-in-glass thermometer work?
A liquid-in-glass thermometer uses a liquid (usually mercury or coloured alcohol) that expands and contracts with temperature changes. As the temperature rises, the liquid expands and moves up the glass tube. The height of the liquid indicates the temperature on a scale marked on the thermometer.

8. What is the freezing point of water in Celsius?
The freezing point of water is 0°C. At this temperature, water changes from a liquid to a solid (ice). This point is crucial for understanding states of matter and is often used as a reference in various scientific measurements and experiments.

9. What is the boiling point of water in Celsius?
The boiling point of water is 100°C. At this temperature, water changes from a liquid to a gas (steam). This is an important temperature to know in cooking and various scientific applications.

10. What is absolute zero?
Absolute zero is the theoretical temperature at which all molecular motion stops. It is defined as 0 Kelvin, which is equivalent to -273.15°C. At absolute zero, particles have the lowest possible energy state, and it serves as a reference point for thermodynamic temperature scales.

11. What is the Kelvin scale?
The Kelvin scale is a temperature scale used in scientific measurements, where 0 K represents absolute zero. Unlike Celsius and Fahrenheit, the Kelvin scale does not use negative numbers. Each degree Kelvin is equal to one degree Celsius, making it convenient for scientific calculations.

12. Why do we use different temperature scales?
Different temperature scales are used for various purposes. Celsius is common in daily life and science in most countries, Fahrenheit is mainly used in the U.S., and Kelvin is preferred in scientific research. Each scale serves specific needs based on the context in which it is used.

13. What is a digital thermometer?
A digital thermometer is an electronic device that measures temperature and displays the result on a digital screen. It provides quick and accurate readings, often used in homes, hospitals, and laboratories. Digital thermometers can measure body temperature, air temperature, and liquid temperature.

14. How does temperature affect states of matter?
Temperature plays a crucial role in determining the state of matter. As temperature increases, solids can melt into liquids, and liquids can evaporate into gases. Conversely, cooling can cause gases to condense into liquids and liquids to freeze into solids. Understanding this helps explain many physical processes.

15. What is thermal expansion?
Thermal expansion is the tendency of materials to change their size or volume when heated. Most materials expand when heated and contract when cooled. This concept is important in various applications, such as construction, where gaps are left in structures to accommodate thermal expansion.

16. What is the difference between heat and temperature?
Heat refers to the energy transferred between objects due to a temperature difference, while temperature measures the average energy of particles in an object. Heat flows from a warmer object to a cooler one, while temperature is a property of the object itself.

17. What happens to air pressure as temperature increases?
As temperature increases, air pressure generally increases. Warm air expands and becomes less dense, which can lead to changes in weather patterns. Understanding this relationship is important in meteorology and atmospheric studies.

18. What is a thermometer made of?
A typical thermometer consists of a glass tube filled with a liquid (mercury or alcohol) that expands with temperature changes. It has a scale marked along the tube to indicate temperature readings. Digital thermometers contain electronic sensors to measure temperature without liquid.

19. How can you measure the temperature of a liquid?
To measure the temperature of a liquid, place the thermometer into the liquid without touching the sides or bottom of the container. Wait a few moments for the reading to stabilise, then check the scale to see the temperature. This ensures an accurate measurement.

20. What is the importance of measuring temperature in cooking?
Measuring temperature in cooking is crucial to ensure that food is cooked thoroughly and safely. Certain temperatures are necessary to kill harmful bacteria and ensure food quality, making temperature measurement a key factor in food preparation.

21. How does temperature affect the density of liquids?
Generally, as the temperature of a liquid increases, its density decreases. This is because warmer liquids expand and take up more space, resulting in a lower density. This concept is important in understanding how substances behave in different conditions.

22. What is a clinical thermometer?
A clinical thermometer is designed specifically for measuring human body temperature. It is usually calibrated in degrees Celsius or Fahrenheit and provides accurate readings for assessing health, especially in medical settings.

23. How do you read a thermometer?
To read a thermometer, ensure it is placed properly in the environment you are measuring. Wait for the liquid to stabilise, and then look at the level of the liquid in the tube. The number at the point where the liquid stops indicates the temperature.

24. What is the effect of temperature on chemical reactions?
Generally, higher temperatures speed up chemical reactions. This is because increased temperature causes particles to move faster and collide more often, leading to more successful reactions. This principle is important in both biology and chemistry.

25. Why is it important to know the temperature in scientific experiments?
Knowing the temperature in scientific experiments is essential because many chemical and physical processes depend on temperature. Accurate temperature measurement helps ensure reliable and valid results, which are crucial for scientific discoveries and understanding natural phenomena.

Extra Questions for Class 6 Science Chapter 7 Temperature and its Measurement

Q1: What is the normal body temperature of a healthy human in Celsius?
A1: The normal body temperature of a healthy human is approximately 37°C.

Q2: Which instrument is used to measure temperature?
A2: A thermometer is used to measure temperature.

Q3: Convert 30°C to Fahrenheit.
A3: To convert Celsius to Fahrenheit, use the formula:
°F = (°C × 9/5) + 32.
So, 30°C = (30 × 9/5) + 32 = 86°F.

Q4: Why is mercury used in thermometers?
A4: Mercury is used in thermometers because it expands and contracts uniformly with temperature changes and is a good conductor of heat. Additionally, it is visible and does not wet the glass tube, making it easier to read.

Q5: What is the freezing point of water on the Fahrenheit scale?
A5: The freezing point of water on the Fahrenheit scale is 32°F.

Q6: True or False: A clinical thermometer can measure temperatures up to 42°C.
A6: True. A clinical thermometer can measure temperatures in the range of 35°C to 42°C, which is suitable for human body temperature.

Q7: Explain why a laboratory thermometer is more suitable for measuring the temperature of boiling water than a clinical thermometer.
A7: A laboratory thermometer is more suitable for measuring the temperature of boiling water because it can measure higher temperatures, typically up to 110°C or more, whereas a clinical thermometer is designed to measure body temperature, which does not exceed 42°C.

Q8: What is absolute zero, and what is its value in Kelvin?
A8: Absolute zero is the lowest possible temperature at which molecular motion stops. It is equivalent to 0 Kelvin (K) or -273.15°C.

Q9: Match the following:

1. Clinical Thermometer | a) Used in scientific experiments

2. Laboratory Thermometer | b) Measures body temperature

3. Kelvin Scale | c) Measures temperature in Kelvin units

A:

1. Clinical Thermometer - b) Measures body temperature

2. Laboratory Thermometer - a) Used in scientific experiments

3. Kelvin Scale - c) Measures temperature in Kelvin units

To do well in Class 6 Science Chapter 7 on Temperature and its Measurement, it's important to focus on key questions and practice them regularly. This PDF gives you the most important questions, extra questions, short answers, and a test paper to help you revise.

Practising these questions will help you understand the concepts better and build your confidence. By revising in this way, you’ll be more prepared and can aim for top marks in your exam. Start practising now and do your best in your Class 6 Science exam!

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