Chapter 07 Temperature and its Measurement Solutions

Chapter 07 Temperature and its Measurement Text Book Solutions

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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. 7.6

Who 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

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

Ans:

• 
  14 °C
  
• 
  17 °C
  
• 
  7.5 °C
  

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) What type of thermometer is it? Laboratory thermometer
(ii) What is the reading of the thermometer? 18 °C
(iii) What is the smallest value that this thermometer can measure? 1 °C

Q8: A laboratory thermometer is not used to measure our body temperature. Give a reason?
Ans: Laboratory thermometers have a wide range (usually from -10°C to 110°C) and do not have the kink to hold the liquid column in place, making them unsuitable for measuring body temperature accurately.

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.

1. 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:

 

(i) What was Vaishnavi’s highest recorded temperature? 40.0 °C
(ii) On which day and at what time was Vaishnavi’s highest temperature recorded? Day 1, at 7pm
(iii) On which day did Vaishnavi’s temperature return to normal? Day 3

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: Use thermometer (a) as it has a range that includes 22.5 °C and can accurately measure this temperature.

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: Each division measures 2 °C.

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.