2. ANSWER STRATEGY PHYSICS QUESTIONS PAPER 3
Written Practical Questions (1 Hours 30 Minutes)
SECTION A
Section A consists of two structured questions. You need to answer all
questions from this section.
This section is allocated a total of 28 MARKS.

3. Section A (Questions 1)
1. The questions in this section are based on experiments that you should
have already done in the laboratory.
2. The questions in this section normally require you to:
- State the variables base on the experiment given. (You are normally
required state the manipulated variable, the responding variable and
the constant variable based on the aim and the procedure of the
experiment)
- Record the data and do the tabulations. (Make sure you know how to
tabulate the data correctly).
- Plot a graph. (Make sure you know how to plot a graph correctly)
- State the relationship between two variables from the graph.
3. You are advised to spend 40 minutes on this section.

4. Section A (Questions 2)
1. The questions from this section also involve the interpretation of graphs.
2. You will also need to know how to determine the gradient and the unit of
the gradient of a graph.
3. The questions from this section may also involve the calculation of
certain quantities. Make sure that you write down all the steps involved
in the spaces provided in the questions paper. (Make sure you know how
to use the value of the gradient in the calculation)
4. You may need to state the precaution of the experiment.
5. You are advised to spend 30 minutes on this section

5. SECTION B
1. Section B consists of two questions. You need to answer ONE question
only from this section.
2. This section is allocated a total of 12 MARKS.
3. You are advised to spend 30 minutes on this section.
4. The questions in this section are normally base on the diagram of a
situation in our daily lives together with a brief write-up on the
situation.
5. You will have to study the situation carefully and try to find the
variables related in the situation.

6. 6. You will also be asked to state one appropriate inference, hypothesis
for an investigation and to describe an experimental framework to test
hypothesis. In your description, you will have to state clearly the
following:
(i) Aim of the experiment
(ii) Variables involved in the experiment
(iiii) List of apparatus and materials
(iv) Arrangement of the apparatus
(v) The procedure of the experiment which includes
- the methods of controlling the manipulated variable
- the method of measuring the responding variable
- the method of repeated experiment
(vi) The way you would tabulate the data
(vii) The way you would analyse the data
7. Make sure that you describe your experiment according to the format
shown above.

7. Section A
[28 marks]
Answer all questions in this section
A student carries out an experiment to investigate the relationship between
the length of wire, l, and its resistance, R.
The arrangement of the apparatus is shown in Diagram 1.1. An ammeter, dry
cells, a rheostat, a switch and piece of constantan sire are connected in
series.
A voltmeter is used to measure the potential difference, V, across the
constantan wire between P and Q.

8. A constantan wire of length, l = 20.0 cm is connected between P and Q. When
the switch is on, the rheostat is adjusted until the ammeter reading is 0.50 A.
The voltmeter reading, V, is as shown in Diagram 1.2 on page 4.
The corresponding voltmeter reading across P and Q are shown in Diagram
1.3, 1.4, 1.5 and 1.6 page 4.

10. (a) For the experiment describe on pages 2 and 3, identify:
The manipulated variable
Length of (wire) / l
[1 mark]
(b)The responding variable
Resistance / R // Potential difference / V // Voltmeter reading //
Voltage
*Rej: voltmeter
[1 mark]
(c) The constant variable
Diameter of wire // Type of wire // Current // Thickness // Cross-
sections of wire // Radius // Ammeter reading // SWG // Resistivity
// Temperature
*Rej: Size, no of battery, emf, dge
[1 mark]

11. b) Based in Diagram 1.2, 1.3, 1.4, 1.5 and 1.6 on page 4:
Record the voltmeter readings, V, in the spaces provided on page 4.
Diagram 1.2 : 0.4 V
Diagram 1.3 : 0.9 V
Diagram 1.4 : 1.3 V
Diagram 1.5 : 1.7 V
Diagram 1.6 : 2.2 V
[2 marks]
(i) Calculate the values of R for each length of wire using the formula
R = V/0.5
Diagram 1.2 : 0.8 Ω [2 marks]
Diagram 1.3 : 1.8 Ω
Diagram 1.4 : 2.6 Ω
Diagram 1.5 : 3.4 Ω
Diagram 1.6 : 4.4 Ω

12. (ii) Tabulate your results for V and R for all values of l, in the space below.
[3 marks]
l / cm V/V R / ohm
20.0 0.4 0.8
40.0 0.9 1.8
60.0 1.3 2.6
80.0 1.7 3.4
100.0 2.2 4.4
Note:
Values of l, V and R shown in the table
State the units of l, V and R correctly
The values of l, V and R are consistent to one or two decimal place.

13. (c) On the graph paper on page 6, plot a graph of R against l.
Show R on the vertical-axis and l on the horizontal-axis 
State the units of the variable correctly / symbol of units 
Both axes are marked with uniform (even) scale 
* (1:1, 1: 2, 1:4, 1:5, 1:10)
* Rej: Odd scale
All five points are plotted correctly 
* 1 (2 mm x 2 mm)
* 5 points – 2m
* 3-4 points – 1m
Best fitted straight line 
* point to the line 5 mm @ 2.5
Show the minimum size of graph at least 5 (y) x 4 (x) ( 10 cm x 8 cm) square 
* Start from the origin until the last point
[7 marks]

14. (d) Based on your graph in 1(c), state the relationship between R and l.
Resistance of wire (R) is directly proportional to the length of wire (l)/
R α l / l α R / Increasing linearly
[1 mark]

16. 2. A student carries out an experiment to investigate the relationship
between the mass, m, of a load placed on a spring and the length, l, of the
spring. The student also determines the spring constant, k.
The result of this experiment is shown in the graph of l against m in
Diagram below.

17. (a) Based on the graph in Diagram 2.1
(i) what happens to l as m increases?
Increases // longer // extended // greater length //
bigger length // higher length
[1 mark]
(ii) determine the value of l when m = 0 g.
l = 9.5 – 10 cm
- show graphical extrapolation correctly
- state the value within acceptable range
[2 marks]

18. (b) The spring constant, k, is given by the formula k = 1/h, where h is the
gradient of the graph.
(i) Calculate the gradient, h, of the graph.
Show on the graph how you calculate h.
[3 marks]
h = (22.5 – 10)/60
= 0.208 cm g-1
- Draw a sufficiently large triangle ≥ 8 cm x 8 cm
- Correct substitution
- State the value within acceptable range and correct unit
* Reject : answer in fraction

19. (ii) Determine the value of k.
[2 marks]
k = 1/h
= 4.81 g cm-1
- Correct substitution
- State the value of k within the acceptable range

20. (c) Another identical spring is connected in series to the end of the
spring. The spring constant, k’, of the two springs in series is given by
1 1 1
the formula 1/k`k= 1/k + 1/k
k'' k
Calculate k’.
k’ = ………………………….
State the value of k’ [2 marks]
2.41 g cm-1 / 2.405 g cm-1
(d) State two precautions that can be taken to improve the accuracy of
the readings in this experiment.
Repeat readings and take average
Eye perpendicular to the scale/reading to avoid parallax error.
Ensure the spring does not swing / at rest when reading is taken.
*Rej: parallax error, parallel
[2 marks]

21. Section B
[12 marks]
Answer any one questions from this section
1. Diagram 3 shows two opaque cups, A and B, containing different
amount of water. A similar coin is placed at the bottom of each cup.
When the coin is observed from the same position, the image of the
coin in cup A cannot be seen, but the image of the coin in cup B can
be seen.

22. Based on your observation on the depth of the water and the
position of the images of the coins:
(a)State one suitable inference
Depth of water affects the position of image //
Position of image depends on the depth of water
*Note:
Must have cause without effect
RV influenced by MV
RV affected MV
MV affects RV
[1 mark]

23. (b)State one hypothesis that could be investigated.
The more the depth of water, the more the depth of the image
// the higher is the image.
*Note: Must have cause and effect
[1 mark]

24. (c) With the use of apparatus such as a tall beaker, pins and other
apparatus, describe an experiment to investigate the hypothesis
stated in 3(b)
In your description, state clearly the following;
(i) The aim of the experiment.
To investigate the relationship between the depth of water
and apparent depth // real depth and apparent depth
*Note: Relate MV and RV
(ii) The variables in the experiment.
Manipulated variable: Real depth
Responding variable: Apparent depth // Depth of image
* Note: Both must correct
Constant variable: Density of water // Refractive index //
Type of liquid

25. (iii) The list of apparatus and materials.
Beaker, Water, Pins, Set of retort stand, Metre rule // Diagram
[1 mark]

26. (iv) The arrangement of apparatus.
- State a functional arrangement of the apparatus
*Note: Functional mean experimental can be done or can get a data.
[1 mark]

27. (v) The procedures of the experiment which include the method of
controlling the manipulated variable and the method of measuring the
responding variable.
State the method to control manipulated variable
Fill beaker with water to a depth of d1 = 10 cm / any number or
symbol/letter
State the method to measure the responding variable
Move the pin outside the beaker to obtain the apparent position of the
pin in the beaker.
Measure the position of the pin from the surface of the water to the
pin.
Repeat the experiment at least 4 times
Repeat the previous steps by increasing the depth of water 15 cm, 20
cm, 25 cm and 30 cm.
[3 marks]

28. (vi) The way to tabulate the data.
Show how the data is tabulated.
*Note: Must have 2 columns
Depth of water, d / cm Apparent depth, h / cm
10
15
20
25
30
(vii) The way to analyse the data.
Apparent depth/cm
- If use symbol, must mention earlier.
- Accept conclusion, statement of variable
related.
- hαd
Depth of water/cm