Candidate Number
Centre Number Candidate Name
UNIVERSITY OF CAMBRIDGE LOCAL EXAMINATIONS SYNDICATE General Certificate of Education Ordinary Level
PHYSICS PAPER 4 Alternative to Practical MAY/JUNE SESSION 2001
5054/4 1 hour
Candidates answer on the question paper. No additional materials are required.
TIME
1 hour
INSTRUCTIONS TO CANDIDATES Write your name, Centre number and candidate number in the spaces at the top of this page. Answer all questions. Write your answers in the spaces provided on the question paper. INFORMATION FOR CANDIDATES The number of marks is given in brackets [ ] at the end of each question or part question.
FOR EXAMINER’S USE 1 2 3 4 5 TOTAL
This question paper consists of 11 printed pages and 1 blank page. SB (ND/PW) QF10455/5 © UCLES 2001
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2 1
A small bird lands and stays on a thin horizontal branch of a tree as shown in Fig. 1.1.
branch
Fig. 1.1 This produces up and down oscillations of the branch. A student counts and times the oscillations, and finds that the time for 10 oscillations is 7.7 s. The bird then flies away. The student has 12 similar coins. Some of them are attached to the spot where the bird had landed as shown in Fig. 1.2. sticky tape
branch
coins
Fig. 1.2 The branch is then made to oscillate. The time for 10 oscillations is obtained with different numbers of coins attached to the branch.
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3
For Examiner’s Use
The student’s results are shown in the table. object on the branch
number of oscillations
time/s
mass of object / g
nothing
10
4.5
0
2 coins
10
6.4
4 coins
10
7.3
bird
10
7.7
6 coins
10
8.0
8 coins
10
8.5
X
Using a balance, the student finds that the mass of 12 coins is 90 g. (a) Complete the table by giving the missing information in the mass column.
[2]
(b) By using the values given in the table, complete the following statement about the mass X of the bird. ‘X is greater than ..................... g but less than ..................... g’. [1] (c) (i)
State the graph that you would plot to help you determine the value of X. .................................................................................................................................
(ii) Explain how you would obtain the value for X from your graph.
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4 2
When you blow into a bottle, as shown in Fig. 2.1, a loud sound may be heard.
Fig. 2.1 You can also make a loud sound using the apparatus shown in Fig. 2.2.
output frequency output terminals
small loudspeaker
signal generator bottle
When full, the bottle holds a volume of 450 cm3 of water
Va
volume of air
Vw
volume of water
Fig. 2.2 The output frequency of the signal generator can be changed. For a given volume Va of air, the sound is loud for only one value of frequency f. Your teacher asks you to find out how the value of the volume Va of air in the bottle affects the frequency at which a loud sound is heard. You pour a known volume Vw of water into the bottle and then determine Va. The loudspeaker is placed over the open top of the bottle and the frequency of the signal generator is adjusted until a loud sound is heard coming from the bottle. All the readings are recorded, including the volume Vb of water that fills the bottle. Vb is found to be 450 cm3. (a) How can you change the volume of air inside the bottle? .....................................................................................................................................[1] (b) What does the volume Va of air, plus the volume Vw of water always equal? Va + Vw = ....................................................................................................................[1]
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5 (c) In the experiment, you determine different values of frequency and different volumes of water and air. In the space below, draw up a table in which you could record all the observations you need to make.
For Examiner’s Use
[4]
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6 3
A student makes an electromagnet by wrapping wire around an iron nail. In one experiment the length of wire used makes a coil of 40 turns. The coil is connected in a series circuit as shown in Fig. 3.1.
nail
A
paper clips
Fig. 3.1 The student uses the variable resistor to obtain six different values of current through the coil. For each value of current, the strength of the electromagnet is measured by the number N of paper clips that the nail can pick up. Three trials are performed and the average number of clips picked up is determined. The student’s values are given in the Table 1 below. number of turns 40 current / A trial 1
number N of paper clips trial 2
trial 3
average number of paper clips
0.5
1
0
0
0.3
1.0
6
9
6
7.0
1.5
12
15
13
13.3
2.0
24
26
23
24.3
2.5
36
37
34
35.7
3.0
37
53
41
43.7
Table 1 (a) Explain why you think that it was a good experimental procedure to take an average of the values obtained for N in the three trials. ......................................................................................................................................... ......................................................................................................................................... .....................................................................................................................................[1] 5054/4/M/J/01
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7 (b) (i)
For Examiner’s Use
Complete Table 2 below. change in current through the coil
change in average number of paper clips picked up
from 0 to 1.0 A
7.0
from 1.0 A to 2.0 A from 2.0 A to 3.0 A Table 2 [2] (ii) With reference to Table 2 explain how you know that the strength of the electromagnet is not directly proportional to the magnitude of the current through the coil. ................................................................................................................................. ................................................................................................................................. ................................................................................................................................. .............................................................................................................................[2] (c) Table 1 shows that for a current of 3.0 A the first two values for N are 37 and 53. The number 53 is 43% larger than 37. Suggest one reason why there is such a large difference between the number of clips. ......................................................................................................................................... ......................................................................................................................................... .....................................................................................................................................[1]
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8
0
10
20
30
40
50
60
70
80
90
10
0
C
10
The thermometer in Fig. 4.1 is a full-size diagram of a centigrade thermometer.
-1 0
4
Fig. 4.1 (a) What range of temperatures may be measured using this thermometer? temperature range = ...................................................................................................[1] (b) On Fig. 4.1 mark the lower fixed point with the letter L and the upper fixed point with the letter U. [1] (c) You dissolve 15 g of common salt in 200 cm3 of water. The salt becomes what is known as a dissolved impurity. The solution is used to discover the effect of the dissolved impurity on the boiling point of water. Further amounts of salt are added and the boiling point determined for each mass. The graph of Fig. 4.2 represents the results of the experiment. 5054/4/M/J/01
For Examiner’s Use
9
For Examiner’s Use
108
P x
Q x
60
70 80 mass/g
x
107 boiling point/°C 106 105
x
104 103
x
102 101 100 99
0
10
20
30
40
50
Fig. 4.2 At the beginning of the experiment the salt dissolves very quickly. It takes longer as more salt is added. At the point marked Q on the graph, not all the salt is dissolved. Describe how the boiling point is changed by the presence of salt as a dissolved impurity. In your description, suggest what has happened at the points P and Q. ......................................................................................................................................... ......................................................................................................................................... ......................................................................................................................................... ......................................................................................................................................... .....................................................................................................................................[3] (d) When determining the upper fixed point of the thermometer it is held in steam. Suggest a reason for this. ......................................................................................................................................... .....................................................................................................................................[1]
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10 5
A student is using a digital ohmmeter. The meter measures directly the resistance of an electric component. Fig. 5.1 shows the use of the ohmmeter to measure the resistance of a thermistor at different temperatures.
112 ohmmeter thermometer
oil thermistor heater Fig. 5.1 The temperature of the oil is increased slowly and the resistance obtained at suitable temperatures. The readings are given in the table below. temperature/°C
22
29
40
52
63
72
82
92
102
resistance/Ω
350 290 205 150 110
84
70
55
40
(a) On page 11 plot the graph of resistance/Ω (y-axis) against temperature/ °C (x-axis). (Please note the instruction about using the graph paper. This is given on the graph paper.) Draw the best smooth curve for the points. (b) (i)
[4]
The thermometer measures the temperature of the oil. How would you perform the experiment to ensure that the thermistor is at the same temperature as the oil? ................................................................................................................................. .................................................................................................................................
(ii) How could you make a parallax error when taking the readings?
................................................................................................................................. .............................................................................................................................[2]
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USE THE GRAPH PAPER THIS WAY ROUND
11
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12 BLANK PAGE
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