CBSE Class 6 Science Chapter 7: Temperature and Its Measurement — Assertion & Reason
CBSE Class 6 Science Assertion & Reason
Expert crafted · Instant PDF download · 2026-27
The following Assertion and Reason questions are based on Chapter 7: Temperature and Its Measurement from the NCERT Class 6 Science textbook Curiosity. Each question has four options — read both the Assertion (A) and Reason (R) carefully before selecting your answer.
How to attempt Assertion & Reason questions:
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is NOT the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is NOT the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
Assertion & Reason Questions
1
Assertion (A): We cannot always rely upon our sense of touch to decide correctly whether a body is hot or cold.
Reason (R): The sense of touch is relative and can give confusing signals, depending on what our hands were exposed to previously.
Reason (R): The sense of touch is relative and can give confusing signals, depending on what our hands were exposed to previously.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. An object might feel cool to a hand that was previously in hot water, and warm to a hand previously in cold water, proving touch is not a reliable measure.
2
Assertion (A): A reliable measure of the hotness or coldness of a body is its temperature.
Reason (R): A hotter body always has a higher temperature than a colder body.
Reason (R): A hotter body always has a higher temperature than a colder body.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Temperature provides an objective, numerical measurement to compare how hot or cold different bodies are.
3
Assertion (A): The normal temperature of every perfectly healthy human being is exactly 37.0 °C.
Reason (R): Normal temperature is the average body temperature of a large number of healthy people.
Reason (R): Normal temperature is the average body temperature of a large number of healthy people.
Answer: (d)
A is false, but R is true. A perfectly healthy person may have a temperature slightly higher or lower than 37.0 °C because it is just an average value, not an absolute rule for every individual.
4
Assertion (A): Mercury thermometers are increasingly being replaced by digital thermometers.
Reason (R): Mercury is a highly toxic substance and is difficult to dispose of safely if a thermometer breaks.
Reason (R): Mercury is a highly toxic substance and is difficult to dispose of safely if a thermometer breaks.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Because of the health and environmental risks associated with mercury spills, safer digital alternatives are preferred.
5
Assertion (A): Infrared thermometers can measure a person's temperature without touching their body.
Reason (R): Non-contact thermometers help reduce the risk of spreading infectious diseases like COVID-19.
Reason (R): Non-contact thermometers help reduce the risk of spreading infectious diseases like COVID-19.
Answer: (b)
Both A and R are true, but R is NOT the correct explanation of A. While R provides the benefit (reducing infection risk), it does not explain the scientific mechanism of how infrared thermometers measure temperature without contact.
6
Assertion (A): A clinical thermometer can be used to measure the temperature of boiling water.
Reason (R): The temperature of boiling water is well within the range of a standard clinical thermometer.
Reason (R): The temperature of boiling water is well within the range of a standard clinical thermometer.
Answer: (c)
Both A and R are false. A clinical thermometer has a narrow range meant only for human body temperatures. Boiling water (100 °C) exceeds its maximum range and will break the thermometer.
7
Assertion (A): A common laboratory thermometer has a range from -10 °C to 110 °C.
Reason (R): Laboratory thermometers are designed to measure a wider range of temperatures than clinical thermometers.
Reason (R): Laboratory thermometers are designed to measure a wider range of temperatures than clinical thermometers.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Because scientific experiments often involve ice, boiling water, and chemical reactions, lab thermometers need a broad temperature range.
8
Assertion (A): While measuring the temperature of a liquid, the laboratory thermometer should be held vertically.
Reason (R): Tilting the thermometer can lead to an inaccurate reading of the liquid column.
Reason (R): Tilting the thermometer can lead to an inaccurate reading of the liquid column.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. To ensure accuracy and to correctly read the scale at eye level, the thermometer must be held straight and vertical.
9
Assertion (A): The temperature of water continuously increases while it is actively boiling.
Reason (R): Boiling water absorbs heat continuously from the burner beneath it.
Reason (R): Boiling water absorbs heat continuously from the burner beneath it.
Answer: (d)
A is false, but R is true. Even though the water absorbs heat, its temperature remains constant at its boiling point until it entirely turns into steam.
10
Assertion (A): The SI unit of temperature is degree Celsius (°C).
Reason (R): The Celsius scale is commonly used in laboratories and for daily weather reports.
Reason (R): The Celsius scale is commonly used in laboratories and for daily weather reports.
Answer: (d)
A is false, but R is true. While the Celsius scale is widely used in daily life, the official SI unit of temperature in scientific work is the kelvin (K).
11
Assertion (A): There is no limit to the lowest temperature that can be achieved in the universe.
Reason (R): Temperature is just a measure of hotness, and objects can infinitely lose heat.
Reason (R): Temperature is just a measure of hotness, and objects can infinitely lose heat.
Answer: (c)
Both A and R are false. According to scientific understanding, there is an absolute limit to how cold things can get, which is absolute zero (-273.15 °C or 0 K).
12
Assertion (A): The reading of a laboratory thermometer must be taken while its bulb is still immersed in the liquid.
Reason (R): As soon as the thermometer is taken out, the liquid column inside begins to fall or rise to match the room temperature.
Reason (R): As soon as the thermometer is taken out, the liquid column inside begins to fall or rise to match the room temperature.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Unlike a clinical thermometer, a lab thermometer does not hold its reading; it instantly reacts to its current environment.
13
Assertion (A): The bulb of a laboratory thermometer should not touch the bottom or sides of the beaker while measuring.
Reason (R): Touching the container will cause the thermometer to measure the temperature of the container itself rather than the liquid.
Reason (R): Touching the container will cause the thermometer to measure the temperature of the container itself rather than the liquid.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. For an accurate reading of the substance, the bulb must be completely surrounded by the liquid without contacting the glass walls.
14
Assertion (A): While reading a thermometer, the eye should be directly in line with the level of the liquid column.
Reason (R): Viewing the liquid level from an angle can result in an incorrect reading due to parallax error.
Reason (R): Viewing the liquid level from an angle can result in an incorrect reading due to parallax error.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. Keeping the eye straight in line with the meniscus ensures the measurement is read exactly as marked on the scale.
15
Assertion (A): A normal human body temperature of 37.0 °C is equivalent to 98.6 °F.
Reason (R): The Celsius and Fahrenheit scales represent different physical amounts of heat in a body.
Reason (R): The Celsius and Fahrenheit scales represent different physical amounts of heat in a body.
Answer: (c)
A is true, but R is false. The two scales represent the exact same physical temperature (the same amount of heat); they just use different numerical values and units to express it.
16
Assertion (A): Human body temperature remains strictly identical regardless of the time of day or physical activity.
Reason (R): The body temperature is influenced by factors such as age, time of day, and activity level.
Reason (R): The body temperature is influenced by factors such as age, time of day, and activity level.
Answer: (d)
A is false, but R is true. Body temperature naturally fluctuates slightly throughout the day and increases with physical exertion.
17
Assertion (A): Pulse rate alone is a highly reliable and definitive indicator of a fever.
Reason (R): While fever affects the pulse rate, many other situations and activities also affect a person's pulse.
Reason (R): While fever affects the pulse rate, many other situations and activities also affect a person's pulse.
Answer: (d)
A is false, but R is true. Because exercise, stress, and other factors change the pulse rate, pulse alone cannot reliably confirm a fever; a thermometer is required.
18
Assertion (A): To measure the temperature of a small child, a digital clinical thermometer can be placed in their armpit.
Reason (R): Armpit measurements are slightly lower (about 0.5 °C to 1 °C) than the actual core body temperature.
Reason (R): Armpit measurements are slightly lower (about 0.5 °C to 1 °C) than the actual core body temperature.
Answer: (b)
Both A and R are true, but R is NOT the correct explanation of A. The reason we use the armpit for children is for safety and convenience, not because it gives a lower reading.
19
Assertion (A): The temperature of ice remains constant while it is melting into water.
Reason (R): The heat supplied during melting is used up in changing the state from solid to liquid, not in raising the temperature.
Reason (R): The heat supplied during melting is used up in changing the state from solid to liquid, not in raising the temperature.
Answer: (a)
Both A and R are true, and R is the correct explanation of A. During a phase change (like melting), the temperature stays stable until all the ice has converted to water.
20
Assertion (A): When writing the unit 'kelvin' in full, it should start with a lower-case letter 'k'.
Reason (R): The symbols of all temperature units (°C, °F, K) are written with capital letters because they are named after scientists.
Reason (R): The symbols of all temperature units (°C, °F, K) are written with capital letters because they are named after scientists.
Answer: (b)
Both A and R are true, but R is NOT the correct explanation of A. Writing 'kelvin' with a lower-case 'k' is a standard grammar rule for SI unit names, whereas capitalization applies only to their symbols (K) or the scale names (Kelvin scale).
❓ Frequently Asked Questions
What is covered in CBSE Class 6 Science Chapter 7 Temperature and Its Measurement?
This chapter covers all key topics from Temperature and Its Measurement as per CBSE 2026-27 syllabus.
Is this Assertion & Reason useful for CBSE board exams?
Yes, designed for CBSE Class 6 board exam preparation covering the complete syllabus.
Are these CBSE Class 6 Science Assertion & Reason updated for 2026-27?
Yes, all content at eBookPublisher is updated as per the latest 2026-27 CBSE syllabus.
How many chapters are in CBSE Class 6 Science?
All chapters of CBSE Class 6 Science are covered at eBookPublisher with free Assertion & Reason for each chapter.
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