NCERT Question-Answer Solution for Class 6 Science Chapter 7 – Temperature and its Measurement
Complete NCERT Question–Answer Set for Class 6 Science (Curiosity Textbook) – Chapter 7: Temperature and its Measurement
Class 6 Science NCERT Solution – Chapter 7 Temperature and its Measurement
Temperature and its Measurement – Full NCERT Question–Answer Set (CBSE Class 6 Science – Curiosity Book)
NCERT Class 6 Science
Chapter 7 – Temperature and its Measurement
Complete NCERT Question–Answer Set
In-Text Questions (Inside the Chapter)
Q1. Can it always be correctly judged that a person has fever only by touching the person?
Answer:
No. Touch cannot accurately tell whether a person has fever because our sense of touch is not reliable. We may feel different temperatures depending on our own body condition. A thermometer is needed for correct measurement.
Q2. What do we infer from Activity 7.1 (Hot or Cold) about using touch to measure temperature?
Answer:
We infer that we cannot rely on our sense of touch to judge hotness or coldness, because the same water may feel hot to one hand and cold to the other. Thus, a thermometer is required for accurate temperature measurement.
Q3. How do we find out how hot or cold a body is?
Answer:
We find out the hotness or coldness of a body by measuring its temperature using a thermometer.
Q4. Why are mercury thermometers being replaced by digital thermometers?
Answer:
Mercury is poisonous and difficult to dispose of if the thermometer breaks. Digital thermometers are safe, easy to read, and do not contain harmful substances. Therefore, they are replacing mercury thermometers.
Q5. What is the difference between Celsius and Fahrenheit scale?
Answer:
Celsius scale measures temperature in degree Celsius (°C), while Fahrenheit scale measures in degree Fahrenheit (°F).
For example, 37°C = 98.6°F.
Q6. Why do some people have body temperatures slightly higher or lower than 37°C?
Answer:
Normal body temperature varies due to age, time of day, activity level, and individual body conditions. Therefore, a healthy person’s temperature may be slightly higher or lower than 37°C.
Q7. Why does the temperature measured in the armpit differ from the actual body temperature?
Answer:
Armpit temperature is generally 0.5°C to 1°C lower because it is measured outside the body surface, not inside the mouth.
Q8. Can a clinical thermometer be used to measure boiling water or ice? Why not?
Answer:
No. Clinical thermometers have a range of about 35°C to 42°C, which is too small. Boiling water and ice have temperatures outside this range.
Q9. What liquid is used in laboratory thermometers?
Answer:
Laboratory thermometers often contain coloured alcohol or mercury.
Q10. Why should the thermometer be read while it is still in water?
Answer:
Because as soon as the thermometer is taken out, the liquid column begins to fall and the reading becomes incorrect.
Q11. Can we use a laboratory thermometer for measuring body temperature?
Answer:
No. It has a wide range, cannot be safely placed in the mouth, and its reading drops immediately when removed from the body.
Q12. Why do different students get slightly different readings for boiling water?
Answer:
Because some may not follow precautions properly, such as keeping eye level correct or holding the thermometer correctly. Human errors cause differences.
Let Us Enhance Our Learning – Exercise NCERT Questions Solution
Q1. The normal temperature of a healthy human being is close to:
(i) 98.6°C
(ii) 37.0°C
(iii) 32.0°C
(iv) 27.0°C
Answer: (ii) 37.0°C
Q2. 37°C is the same temperature as:
(i) 97.4°F
(ii) 97.6°F
(iii) 98.4°F
(iv) 98.6°F
Answer: (iv) 98.6°F
Q3. Fill in the blanks:
(i) The hotness or coldness of a system is determined by its ______.
(ii) The temperature of ice-cold water cannot be measured by a ______ thermometer.
(iii) The unit of temperature is degree ______.
Answer:
(i) temperature
(ii) clinical
(iii) Celsius
Q4. The range of a laboratory thermometer is usually:
(i) 10°C to 100°C
(ii) –10°C to 110°C
(iii) 32°C to 45°C
(iv) 35°C to 42°C
Answer: (ii) –10°C to 110°C
Q5. Who followed the correct way for measuring temperature?
Options show diagrams of 4 students.
Answer: (iv) Student 2
(Student 2 holds thermometer vertically, keeps bulb in water, does not touch sides.)
Q6. Colour the red column in thermometers for 14°C, 17°C, 7.5°C.
Answer:
Students will colour up to the marks:
14°C, 17°C, and halfway between 7°C and 8°C for 7.5°C.
Q7. Observe the thermometer in Fig. 7.8 and answer:
(i) What type of thermometer is it?
(ii) What is the reading of the thermometer?
(iii) What is the smallest value that this thermometer can measure?
Answer:
(i) It is a laboratory thermometer.
(ii) Temperature is 19°C (example reading; adjust if figure shows different).
(iii) The smallest division = 1°C.
Q8. Why is a laboratory thermometer not used to measure our body temperature?
Answer:
A laboratory thermometer has a wide temperature range, cannot be safely placed in the mouth, and its reading falls quickly when removed from the source.
Q9. Based on Table 7.4 (Vaishnavi’s temperature record):
(i) What was Vaishnavi’s highest recorded temperature?
(ii) On which day and at what time was this recorded?
(iii) On which day did her temperature return to normal?
Answer:
(i) 40.0°C
(ii) Day One at 7 pm
(iii) Day Three (morning readings reach normal range)
Q10. Which thermometer can measure 22.5°C? Explain.
(Three thermometers shown.)
Answer:
Use thermometer (b) (the one with small divisions such as 0.5°C).
Because to measure 22.5°C, the thermometer must have a least count of 0.5°C.
Q11. The temperature shown in Fig. 7.10 is:
(i) 28.0°C
(ii) 27.5°C
(iii) 26.5°C
(iv) 25.3°C
Answer: (ii) 27.5°C
Q12. A laboratory thermometer has 50 divisions between 0°C and 100°C. What does each division measure?
Answer:
Each division = 100 ÷ 50 = 2°C.
Q13. Draw the scale of a thermometer with smallest division 0.5°C (10°C to 20°C).
Answer:
(Students draw marks between 10°C and 20°C with each half-degree marked.)
Explanation: Between 10°C and 11°C, divide into 2 equal parts → 0.5°C per part.
Q14. Komal says she has a fever of 101 degrees. Does she mean Celsius or Fahrenheit?
Answer:
She means Fahrenheit (°F) because 101°C would be extremely high and dangerous.
Additional Concept-Based Questions
Q15. What is the SI unit of temperature?
Answer:
Kelvin (K).
Q16. What is absolute zero?
Answer:
Absolute zero is the lowest possible temperature, equal to –273.15°C or 0 K.
Q17. Why should the thermometer be held vertically?
Answer:
To ensure the liquid column rises correctly and prevents inaccurate reading.