NCERT Solutions for Class 6 Chapter 7: Temperature and its Measurement

NCERT Solutions for Class 6 Chapter 7: Temperature and its Measurement

Page 123

Question 1.
Can it always be correctly judged, that a person has fever, only by touching the person?
Answer:

• It cannot always be correctly judged that a person has fever, only by touching the person.
• If a person has a normal body temperature and the hand touching that person is cold, the person will feel to be warm to the hand. If the hand touching a person is warm, the person with fever may be felt as at normal temperature.
  For correct judgement that a person has fever or not, we must use clinical thermometer correctly.

Page 128

Question 2.
Do small children generally have slightly higher body temperatures as compared to adults?
Answer:
Yes, small children usually have slightly higher body temperatures compared to adults. This is because their bodies are working hard to grow quickly, which makes more heat. For kids, a normal body temperature is usually between 37.0°C and 37.5°C . For adults, it’s a bit lower, usually between 36.1°C and 37.2°C.

Question 3.
Do old people, even when healthy, generally have lower body temperatures than young adults?
Answer:
Yes, even healthy older people generally have lower body temperatures than young adults. As people age, their bodies slow down and don’t produce as much heat. For older adults, normal body temperature is often around 36.2°C to 36.8°C, which is slightly lower than the typical range for younger adults.

Page 129

Question 4.
Can a clinical thermometer be used for measuring the temperature of boiling water? Or for measuring the temperature of ice?
Answer:
A clinical thermometer has a range of 35 °C to 42 °C. The temperature of boiling water is 100 °C and is beyond the range of a clinical thermometer. Also the temperature of ice is 0 °C or below, and is beyond the range of clinical thermometer.
Therefore a clinical thermometer cannot used for measuring the temperatures of boiling water or of ice.

Pages 137-140

Let Us Enhance Our Learning

Question 1.
The normal temperature of a healthy human being is close to
(i) 98.6 °C
(ii) 37.0 °C
(in) 32.0 °C
(iv) 27.0 °C
Answer:
(ii) 37.0 °C

Question 2.
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

Question 3.
Fill in the blanks:
(i) The hotness or coldness of a system is determined by its ___________.
Answer:
Temperature

(ii) The temperature of ice-cold water cannot be measured by a ___________ thermometer.
Answer:
Clinical

(iii) The unit of temperature is degree ___________.
Answer:
Celsius

Question 4.
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

Question 5.
Four students used a laboratory thermometer to measure the temperature of water as shown in the figure

Who do you think followed the correct way for measuring temperature?
(i) Student 1
(ii) Student 2
(iii) Student 3
(iv) Student 4
Answer:
(ii) Student 2

Question 6.
Colour to show the red column on the drawings of thermometers (Fig. 8) as per the temperatures written below :

Answer:
Hint : In the first thermometer for 14°C colour up to two small lines above mark 10 (each small line indicates 2 degrees Celsius).
In the second thermometer for 17°C colour up to seven small lines above mark 10 (each small line indicates 1 degree Celsius).
In the third thermometer colour up to fifteen small lines above mark 0 (each small line indicates 0.5 degree Celsius). Red lines are marked alongside the respective thermometers for information.

Question 7.
Observe the part of thermometer shown in Fig. and answer the following questions:

(i) What type of thermometer is it?
(ii) What is the reading of the thermometer?
(in) What is the smallest value that this thermometer can measure?
Answer:
(i) The lowest mark on the thermometer is -10’ so this is a laboratory thermometer that has a measuring range of -10 °C to 110 °C.
(ii) The reading of the thermometer is 26 °C.
(iii) There are 10 small line marks between any 10 degrees (0-10, 10-20 and so on) on the thermometer. So the thermometer can measure the smallest value of – 10°C.

Question 8.
A laboratory thermometer is not used to measure our body temperature. Give a reason.
Answer:
A laboratory thermometer has a wide range around -10 0 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.

Question 9.
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 the table given.

(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?
Answer:
(i) Vaishnavi’s highest recorded temperature was 40.0° C.
(ii) Vaishnavi’s highest temperature was recorded on day One at 7 pm .
(iii) Vaishnavi’s temperature returned to normal orn day Three.

Question 10.
If you have to measure the temperature 22.5 °C, which of the following three thermometers will you use (Fig.)? Explain.

Three thermometers
Answer:
We will use thermometer
(b) Thermometer (a) can measure the smallest value of 1°C and thermometer (c) can measure the smallest value of 2°C as per the small line markings on these. Only thermometer (b) has the markings on it to measure the smallest value of 0.5°C which is necessary for measuring a temperature of 22.5 °C.

Question 11.
The temperature shown by the thermometer in the given figure is

(i) 28.0° C
(ii) 27.5° C
(iii) 26.5° C
(iv) 25.3° C
Answer:
(ii) 27.5° C

Question 12.
A laboratory thermometer has 50 divisions between 0 °C and 100 °C. What does each division of this thermometer measure?
Answer:
Each division measures 2° C.

Question 13.
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.
Answer:

Question 14.
Someone tells you that she has a fever of 101 degrees. Does she mean it on the celsius scale or Fahrenheit scale.
Answer:
If someone tells me that she has a fever of 101 degrees, she means it on the Fahrenheit scale. A body temperature of 101 degrees Fahrenheit indicates a fever, as the normal human body temperature is approximately 98.6°F.

In Celsius, 101 degrees would be extremely high and life-threatening, since normal body temperature is around 37°C and 101°C is far beyond human tolerance. Therefore, it is clear that the fever is being referred to in Fahrenheit.

BrightWay Coaching Academy