# DAV Class 5 Maths Chapter 15 Brain Teasers Solutions

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.
(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

Question 1.
(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