The DAV Class 5 Maths Solutions and **DAV Class 5 Maths Chapter 15 Brain Teasers** Solutions of Temperature offer comprehensive answers to textbook questions.

## DAV Class 5 Maths Ch 15 Brain Teasers Solutions

Question 1.

Tick (✓) the correct answer.

(a) Water freezes at

(i) 0°C

(ii) 0°F

(iii) 32°C

(iv) 100°C

Solution:

(i) 0°C

(b) Which of the following would a thermometer display on a very hot day?

(i) 15°C

(ii) 22°C

(iii) 47°C

(iv) 4°C

Solution:

(iii) 47°C

(c) 28.5°C = _____ °F

(i) 83.3

(ii) 51.3

(iii) 60.5

(iv) 38.5

Solution:

(i) 83.3

(d) 100 divisions on a Celsius Scale thermometer is equal to _______ divisions on a Fahrenheit Scale thermometer.

(i) 32

(ii) 180

(iii) 80

(iv) 212

Solution:

(ii) 180

(e) 120.2°F = _______ °C

(i) 88

(ii) 37

(iii) 49

(iv) 55

Solution:

(iii) 49

Question 2.

Fill in the blanks.

(a) Temperature is a measure of ______ or ______ of a body.

Solution:

hotness, coldness

(b) We use a thermometer to measure the ______ of a body.

Solution:

temperature

(c) A doctor uses a ______ thermometer to measure the temperature of a patient.

Solution:

clinical thermometer

(d) Celsius and Fahrenheit are the two ______ used in a thermometer.

Solution:

scales

(e) 212°F is the ______ point of water in the Fahrenheit Scale.

Solution:

boiling

(f) The ______ scale is used in a clinical thermometer.

Solution:

Fahrenheit

(g) 0°C = ______ °F and 212°F = ______ °C.

Solution:

32°F, 100°C

Question 3.

Convert the following temperature into the other scale.

(a) 70°C

Solution:

70°C

Step 1: 70 × \(\frac{9}{5}\) = 126

Step 2: 32 + 126 = 158

So, 70°C = 158°F

(b) 104°F

Solution:

104°F

Step 1: 104 – 32 = 72

Step 2: 72 × \(\frac{5}{9}\) = 40

So, 104°F = 40°C

(c) 0°C

Solution:

0°C

Step 1: 0 × \(\frac{9}{5}\) = 0

Step 2: 32 + 0 = 32

So, 0°C = 32°F

(d) 15°C

Solution:

15°C

Step 1: 15 × \(\frac{9}{5}\) = 27

Step 2: 32 + 27 = 59

So, 15°C = 59°F

(e) 59°F

Solution:

59°F

Step 1: 59 – 32 = 27

Step 2: 27 × \(\frac{5}{9}\) = 15

So, 59°F = 15°C

(f) 9°C

Solution:

9°C

Step 1: 9 × \(\frac{9}{5}\) = \(\frac{81}{5}\)

Step 2: 32 + \(\frac{81}{5}\)

= \(\frac{160+81}{5}\)

= 48.2

So, 9°C = 48.2°F

Additional Questions

Question 1.

One-word answer.

(a) The instrument used to measure the temperature of a body.

Solution:

Thermometer

(b) Unit used to measure the temperature.

Solution:

Degree

(c) Freezing point of water in Celsius Scale.

Solution:

0°C

(d) Boiling point of water in Celsius Scale.

Solution:

100°C

(e) Temperature of a healthy adult is ___________ or ___________

Solution:

98.6°F, 37°C

Question 2.

What is the clinical thermometer? What is its use?

Solution:

A doctor’s thermometer is called a clinical thermometer. Doctors use this thermometer to measure the temperature of their patient.

Question 3.

Convert the following temperature in the Fahrenheit Scale.

(a) 10°C

Solution:

10°C

Step 1: 10 × \(\frac{9}{5}\) = 18

Step 2: 32 + 18 = 50

So, 10°C = 50°F

(b) 120°C

Solution:

120°C

Step 1: 120 × \(\frac{9}{5}\) = 216

Step 2: 32 + 216 = 248

So, 120°C = 248°F

(c) 95°C

Solution:

95°C

Step 1: 95 × \(\frac{9}{5}\) = 171

Step 2: 32 + 171 = 203

So, 95°C = 203°F

(d) 135°C

Solution:

135°C

Step 1: 135 × \(\frac{9}{5}\) = 243

Step 2: 32 + 243 = 275

So, 135°C = 275°F

Question 4.

Convert the following temperature in the Celsius Scale.

(a) 32°F

Solution:

32°F

Step 1: 32 – 32 = 0

Step 2: 0 × \(\frac{5}{9}\) = 0

So, 32°F = 0°C

(b) 80°F

Solution:

80°F

Step 1: 80 – 32 = 48

Step 2: 48 × \(\frac{5}{9}\) = 26.6

So, 80°F = 26.6 °C

(c) 250°F

Solution:

250°F

Step 1: 250 – 32 = 218

Step 2: 218 × \(\frac{5}{9}\)

= \(\frac{1090}{9}\)

= 121.1

So, 250°F = 121.1°C

Question 5.

State whether the following statements are True or False:

(a) 100 divisions on the Celsius Scale Thermometer is equal to 170 divisions in the Fahrenheit Scale Thermometer.

Solution:

False

(b) Water freezes at 0°F.

Solution:

False

(c) In 20°C, 35°C, 40°C, temperature 40°C display a very hot day.

Solution:

True

(d) 28.5°C = 82.3°F

Solution:

False

(e) 0°C = 32°F

Solution:

True

Question 6.

Write the freezing point and boiling point on both scales.

Solution:

The Freezing Point and boiling point on the Celsius Scale are 0°C and 100°C respectively. The freezing point and boiling point on the Fahrenheit scale are 32°F and 212°F respectively.

Question 7.

How freezing point different from the boiling point?

Solution:

Water becomes ice at freezing point and it starts boiling at boiling point.

Question 8.

Which scale is used in clinical thermometers?

Solution:

Fahrenheit Scale

Question 9.

Convert the following temperature into other scales.

(a) 8°C

Solution:

8°C

Step 1: 8 × \(\frac{9}{5}\) = 14.4

Step 2: 32 + 14.4 = 46.4

So, 8°C = 46.4°F

(b) 50°C

Solution:

50°C

Step 1: 50 × \(\frac{9}{5}\) = 90

Step 2: 32 + 90 = 122

So, 50°C = 122°F

(c) 212°F

Solution:

212°F

Step 1: 212 – 32 = 180

Step 2: 180 × \(\frac{5}{9}\) = 100

So, 212°F = 100°C

(d) 104°F

Solution:

104°F

Step 1: 104 – 32 = 72

Step 2: 72 × \(\frac{5}{9}\) = 40

So, 104°F = 40°C

Question 10.

Write the scientist name who invent Fahrenheit Scale.

Solution:

G.Fahrenheit