Temperature and its Measurement NCERT Solutions | Science Class 6 PDF Download

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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
Ans: (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
Ans: (iv) 98.6 °F

Q3: Fill in the blanks:
(i) The hotness or coldness of a system is determined by its _______ .
Ans: The hotness or coldness of a system is determined by its temperature.

(ii) The temperature of ice-cold water cannot be measured by a  _______ thermometer.
Ans: The temperature of ice-cold water cannot be measured by a clinical thermometer.

(iii) The unit of temperature is degree  _______ .
Ans: The unit of temperature is degree 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
Ans: (ii) –10 °C to 110 °C

Q5:  Four students used a laboratory thermometer to measure the temperature of water as shown in Fig. 7.6:
Fig. 7.6Who do you think followed the correct way for measuring temperature?  
(i) Student 1
(ii) Student 2
(iii) Student 3
(iv) Student 4
Ans: (iii) Student 3
Student 2 is measuring the temperature correctly because the thermometer is fully in the water and not touching the sides or bottom of the container. This way, it only measures the water's temperature.

Q6: Colour to show the red column on the drawings of thermometers (Fig. 7.7) as per the temperatures written below:
Ans: 

Q7: Observe the part of thermometer shown in Fig. 7.8 and answer the following questions:
(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?
Ans: 
(i) This is a laboratory thermometer, characterised by its long, narrow tube and a scale that typically ranges beyond the human body temperature range. 
(ii) The thermometer reading is 15.4°C. This is determined by noting the level of the red liquid column, which is slightly above the 15°C mark, with four small divisions (each representing 0. 1°C) above it.
(iii) The smallest value that this thermometer can measure is — 10°C. The small divisions between the larger degree markings, each representing 0.1°C.

Q8: A laboratory thermometer is not used to measure our body temperature. Give a reason?
Ans: A laboratory thermometer is not used to measure our body temperature because it is designed to measure temperatures over a broader range and must be kept upright, making it inconvenient and potentially unsafe for measuring body temperature.

Q9: Vaishnavi has not gone to school as she is ill. Her mother has kept a record of her body temperature for three days as shown in Table 7.4.
(i) What was Vaishnavi’s highest recorded temperature?
(ii) On which day and at what time was Vaishnavi’s highest temperature recorded?
(iii) On which day did Vaishnavi’s temperature return to normal?
Ans: 

Vaishnavi's body temperature record:
(i) Vaishnavi's highest recorded temperature was 40.0ºC.
(ii) Vaishnavi's highest temperature was recorded on Day One at 7 pm.
(iii) Vaishnavi's temperature returned to normal on Day Three.

Q10: If you have to measure the temperature 22.5 °C, which of the following three thermometers will you use (Fig. 7.9)? Explain.
Ans: The correct thermometer to use for measuring 22.5°C is (b).
Thermometer (b) shows a reading closest to 22.5°C, which is just between the 20°C and 25°C marks. The other thermometers, (a) and (c), display much lower readings and are not close to the desired temperature. Therefore, thermometer (b) is the best option for accurately measuring 22.5°C.

Q11: The temperature shown by the thermometer in Fig. 7.10 is  (i) 28.0 °C
(ii) 27.5 °C
(iii) 26.5 °C
(iv) 25.3 °C
Ans: (ii) 27.5 °C

Q12: A laboratory thermometer has 50 divisions between 0 °C and 100 °C. What does each division of this thermometer measure?  
Ans: A laboratory thermometer with 50 divisions between 0°OC and 100°C means each division represents a specific temperature increment. To determine the value of each division, divide the total temperature range by the number of divisions. Here, the range is 100°C (from 0°C to 100°C) and there are 50 divisions. Therefore, each division measures:
Value of each division = 100°C/50 = 2°C
Thus, each division on this laboratory thermometer represents 2°C. This allows for measurements to be read with an accuracy of 2°C increments.

Q13: Draw the scale of a thermometer in which the smallest division reads 0.5 °C. You may draw only the portion between 10 °C and 20 °C.
Ans: 
The scale will have 20 divisions between 10 °C and 20 °C, with each division representing 0.5 °C.

Q14: Someone tells you that she has a fever of 101 degrees. Does she mean it on the Celsius scale or Fahrenheit scale?
Ans: She means it on the Fahrenheit scale.