# Phy Bk Ans 1

Topics: Thermodynamics, Energy, Temperature Pages: 60 (9394 words) Published: November 20, 2011
1 Heat and Gases Chapter 1 Temperature and Thermometers
New Senior Secondary Physics at Work  Oxford University Press 2009 1
1 Temperature and Thermometers
Practice 1.1 (p. 10)
1 B
2 D
3 A
4 Temperature is a measure of the degree of
hotness of an object.
5 (a) On the Celsius temperature scale, the
lower fixed point is the ice point (0 C)
and the upper fixed point is the steam
point (100 C).
(b) We can reproduce the lower and upper
fixed points by using pure melting ice and
pure boiling water at normal atmospheric
pressure respectively.
6 (II), (IV), (V), (I), (III)
7 Let T be the temperature when the thread is
7.7 cm long.
100 0
0

T  =
18.2 3.2
7.7 3.2

T = 30 C
8
The length of the mercury column at 100 C is
25 cm.
9 Let x be the column length for 37 C.
21 6
6

x  =
80 0
37 0

x = 12.9 cm
10 According to the kinetic theory, all matter is
made up of particles. For solids, the particles
are held in position by strong forces and so
they have fixed shapes.
For liquids and gases, the particles are held by
weaker forces and can move from one place to
another. Therefore, they do not have fixed
shapes.
Practice 1.2 (p. 16)
1 D
2 C
3 A
4 (a) Thermistor thermometer/ liquid-in-glass
thermometer
(b) Resistance thermometer/ alcohol-in-glass
thermometer
(c) Resistance thermometer
(d) Liquid-in-glass thermometer/ infra-red
thermometer/ thermistor thermometer/
liquid crystal thermometer
5 (a) The curvature of the bimetallic strip.
(b) It consists of a bimetallic strip which is
made up of two strips of different metals.
The metals expand at different rates as
they are heated. The different expansions
of strips make the bimetallic strip bend
one way. As a result, a particular curvature
of the bimetallic strip represents a
particular temperature.
1 Heat and Gases Chapter 1 Temperature and Thermometers
New Senior Secondary Physics at Work  Oxford University Press 2009 2
6 Let T be the temperature measured.
100 0
0

T  =
120 35
80 35

T = 52.9 C
Revision exercise 1
Multiple-choice (p. 19)
1 D
2 B
3 B
4 C
80 25
25

R  =
100 0
40 0

R = 47 units
5 B
6 C
100 0
0

T  =
90 10
40 10

T = 37.5 C
7 A
8 A
Conventional (p. 20)
1 Choose the ice point and the steam point as the
lower fixed point and the upper fixed point
respectively. (1A)
Then divide the range between these fixed
points into 100 equal divisions. (1A)
Each division is 1 C. (1A)
The lower fixed point is taken as 0 C and the
upper fixed point is taken as 100 C. (1A)
2
100 0
0

x  =
24.6 3.7
12.0 3.7

(1M)
x = 39.7 C (1A)
3 (a) Let T be the temperature when the length
of the alcohol column is 15.6 cm.
100 0
0

T  =
18.4 4.2
15.6 4.2

(1M)
T = 80.3 C (1A)
(b) Let x be the length of the alcohol column
at 30 C.
18.4 4.2
4.2

x  =
100 0
30 0

(1M)
x = 8.46 cm (1A)
4 (a) TN = TC 
100
33 (1M)
= 250 
100
33
= 82.5 N (1A)
(b) TN = TC 
100
33
=9
5  TF  32
100
33 (1M)
=
TF  32
60
11 (1A)
5 (a)
(Correct labelled axis) (1A)
(Correct points) (1A)
(A smooth curve passing through all data
points) (1A)
(b) 32 C (1A)
1 Heat and Gases Chapter 1 Temperature and Thermometers
New Senior Secondary Physics at Work  Oxford University Press 2009 3
6 (a) A rotary thermometer measures
temperature by measuring the curvature of
the bimetallic strip. (1A)
The bimetallic strip consists of two metal
strips which expand at different rates when
heated to cause a change in curvature of
the strip. (1A)
If a strip with only one kind of metal is
used, it would only expand but not bend
when heated. (1A)
(b) Zinc (1A)
Figure a shows that zinc expands more
when heated. Therefore, zinc corresponds
to metal A which expands more as shown
in Figure b. (1A)
7 (a) Water freezes at temperatures below the
ice point and vaporizes at temperatures
above the steam point. (1A)
The...