TECHNIQUE OF ANSWERING SPM

PHYSICS PAPER 2 [4321/2]

ANSWER STRATEGY PHYSICS QUESTIONS PAPER 2

Subjective Questions (2 Hours 30 Minutes)SECTION A

Section A of paper 2 consists of 8 questions. You will have to answer all the 8 questions in this section.

The total in Section A is 60 marks You are advised to spend 90 minutes on this section. Spending more than 90 minutes on this section will result in having insufficient time to answer questions in Sections B and C. Before attempting to answer questions, read the questions at least twice and highlight the key words provided so that you will not go out of point.

Write down all the steps in the spaces provided in the questions paper, including the formula used.

A section that is allocated only 1 mark will require a short answer. On the other hand, a section that is allocated 3 marks will require you to state 3 properties or characteristic associated with the particular section.

Answer all the 8 questions within the 90 minutes allocated.

Do not force yourself to answer Questions 1 first if you are not too sure of the answers. Answer questions that you are most sure of first

SECTION B Section B consists of two questions. You need to answer only ONE question from this section.

The marks allocated for this section is 20 marks. You are advised to spend 30 minutes on this section.

The questions from section B are normally preceded by a diagram that shows a certain state or situation that is related to a specific Physics concept. You are normally asked to state the characteristics shown in the diagram and also to state the Physics principles involved.

Study the marks allocated to each section or sub-section in the questions. The marks allocated in each section may be as high as 10 marks.

In such cases, make sure that you have at least 10 points or properties related to the section as each point is normally allocated

1 mark.

SECTION C Sections C consists of two questions. You need to answer ONE question only from this section.

The marks allocated for this section is 20 marks. You are advised to spend 30 minutes on this section.

The questions from Section C are normally preceded by a table that is related to a specific Physics concept,

The questions in this section normally require you to state a certain principle or to explain certain properties or characteristics based on the information given.

Study the marks allocated to each section or sub-section in the questions. The marks allocated in each section may be as high as 10 marks. In such cases, make sure that you have at least 10 points or properties related to the section as each point is normally allocated 1 mark.

TYPES OF QUESTIONS IN PAPER 2 SPM PHYSICS

Question No.1 - No.4(Knowledge, Understanding and Application)

Questions No.5, No.6 and No.9/No.10 (Conceptualizing)

Questions No. 7 and No.9/No.10 (Problem Solving)

Questions No. 8 and No.11/No.12 (Making Decision)

Question No.1 - No.4(Knowledge, Understanding and Application)

Understand the tasks Refer to the marks stated- 1 point for 1 mark

Answer in simple words but meaningful related to physics concept Use correct terminology

Calculation: - Choose & write the relevant formula - Substitute the values correctly - Answer with correct unit

Understanding and qualitative application - explain step by step [imaging the marker does not know the physics]

Example 1 – Q21. Diagram 2 shows a water tank that supplies water to a block of flats. The water flows to each unit of the flat due to water pressure.

(a) What is meant by pressure?Force per unit area // Force ÷ Area //

F/A, where; F is force, A is area [1 mark](b) A water tank with a height of 3.0 m is

fully filled with water. Calculate the pressure at the base of the water tank.

[Density of water = 1000 kg m-3]P = hg = 1000 x 9.8 x 3 = 29400 N m-2 // 2.94 x 104 N m-2 / Pa /

kgms-2m-2 / kgm-1s-2[2 marks]

(c) Based in Diagrams 2, compare the water pressure at P and Q. Explain your answer.

Pressure at Q is higher // Pressure at P is lower // Q > P // Q is higher // Q is more // Q is bigger // Q is more than P

Depth at Q is higher // Depth at P is lower // hQ > hP // HQ > HP / Q is deeper // Pressure increases as the depth increases

[2 marks]

Example 2 – Q3A SPM 2007

(a) Name the heat energy, Q1, which is absorbed from R to S. Latent heat // Specific latent heat (of fusion)

[1 mark]

(b) State one reason why the temperature at R and S is the same even though heat is supplied.

The heat needed to break the bonds between molecules // molecules move further apart // to change solid to liquid // to

change physical form // kinetic energy doesn’t change

[1 mark]

(c) Calculate the het energy, Q2, which is absorbed from S to T.

[The specific heat capacity of water, C=4200 J kg-10C-1]

Q = mcθ = 1.0 x 4200 x 100 = 420 000 J // 4.2 x 105 J // 420 kJ

[2 marks]

Questions No.5, No.6 and No.9 or No.10 (Conceptualizing)

Every items starting with stimulus (situation). Stimulus or situation can be in diagram, table, chart or graph.

Understand the tasks: - Comparison :State the similarities and differences (if there is any) - Differences: State characteristics that are different - Similarities : State the same characteristics

Relationship: directly proportional/ inversely proportional/ When ……. increases, ……… Increases/decreased.

Name the law/principle/concept involved.

Example 1 – Q5A SPM 20061. Diagram 5.1 shows the situation of a sheet of paper before and when air is blown.

Diagram 5.2 shows the situation of the canopy before the lorry moves and when the lorry moves at high speed.

(a)What is meant by speed?The rate of change of distance with time / v=s/t ; s = distance, t = time

[1 mark](b) Based in diagram 5.1 and diagram 5.2: (i) State two similarities for the situation in Diagram 5.1 and Diagram 5.2.

- No air movement, the paper and the canopy will not lift up/at rest/not moves

- Paper and canopy lift up when the air moves.

[2 marks](ii) Compare the air pressure above and below the paper when air is blown.

- Air pressure above the paper is lower/air pressure below is higher

[1 mark]

(iv) Name the principle involved in 5(b)(iii). Bernoulli’s

[1 mark]

(iii) Relate the speed of the air to the pressure of the air.

High speed, low pressure / inversely proportional

[1 mark]

Example 1- Q6 SPM 2009

(a) Observe diagram 6.1 and diagram 6.2 (i) Compare the depths of the water in region X and region Y.

X is deeper / bigger / higher / X > Y / Y < X

[1 mark]

(ii) Compare the wavelengths of the waves in region X and region Y.

X is longer / X > Y / Y < X [1 mark](iii) Relate the depth of water to the wave

length of the waves.The deeper the water, the longer the

wavelength / wavelength is directly proportional to the depth of the water / h

[1 mark](iv) Name the wave phenomenon involvedRefraction / Refract

[1 mark]

(v) Explain why the wave front of sea water will follow the shape of the shore when it approaches the shore.

- The depth of the water decreasing / move in shallow area- The velocity is decreasing / wavelength is decreasing / decreasing- Refraction occurs / bending / change direction /diagram

[3 marks]

By using a diagram

Example 2 – Q1B SPM 2011

Diagram 9.1 Diagram 9.21. Using Diagram 9.1 and Diagram 9.2, compare the thickness, the focal length and power of the lens. Relate the thickness of the lens with the focal length to make a deduction regarding the relationship between thickness of the lens and the power of lens.- Lens in diagram 9.1 is thinner- Focal length in diagram 9.1 is longer- Power of lens in diagram 9.1 is lower- The thinner the lens the longer the focal length- The thinner the lens the lower the power

[5 marks]

Example 3 – Q1B SPM 20092. Diagram 9.1 shows the effect of pressure on a sandy beach when a man sits on a chair. Diagram 9.2 shows the same man sitting on the same chair after a piece of plank is placed under the chair.

(a) What is the meaning of pressure?Force per unit area / P = F/A ; where F =

force, A = area[1 mark]

(b) Observe diagram 9.1 and diagram 9.2. Compare the depth of sinking, the load and the area of contact with the sandy beach.

Relate the depth of sinking with the pressure exerted by the chair to make a deduction on the relationship between the pressure and the area of contact in this situation.

- Depth of sinking in 9.1 is deeper than in diagram 9.2

- The weight of the man in diagram 9.2 and 9.1 is equal

- Area contact in diagram 9.2 is larger than 9.1

- The depth of sinking I increases, pressure increases / d P / h P

- As the area of contact increases, the pressure exerted decreases / P 1/A

[5 marks]

Questions No. 7 and No.9 or No.10 (Problem Solving)

Structured Question1. Very sure of the concept / understand the working principle of apparatus and its function.2. Understand the questions / follow the instructions given.3. State the methods and reasons / explanations.

Essay type question: 1. Open type question

1. Understand the problem given2. State the

method/suggestion/design/modification to solve the problems

3. State the explanation for the each method /suggestion/ design

4. Answer in table form for suggested modifications. e.g

Modifications

Explanation

2. Guided type Question (usually working principle of apparatus)

1. Follow the instruction in the question.2. Answer can be in the form of diagram or essay.3. State the method/ways and reasons.Common mistakes:

1. Suggestion of problem solving does not based on relevant physical concept2. Give wrong/irrelevant explanation/reason3. Give redundant/overlap suggestion/method

Example 5: Q9B SPM 20081. Diagram 9.3 shows a pole vaulter performing a jump.

Using appropriate physics concepts, explain the use of suitable equipment and techniques to improve his performance.Your answer should include the following aspects:(i) Vaulter’s attire(ii) Vaulter’s movement(iii) Pole used(iv) Safety

[10 marks]

Modifications ExplanationTight and light attire / spiked shoes

1Less air friction / increases the speed

1

Sprint / Increases speed 1

To increases kinetic energy / momentum

1

More elstic / light / bends easily 1

Easily bend / easily carried / increase the potential elastic energy

1

Strong pole 1 Not easily broken 1

Use thicker mattress 1

Increases collision time / reduce impulsive force

1

Example 2 – Q9B SPM 20072. Diagram 9.6 shows a sailboat.

Your are required to gives some suggestions to design a sailboat which can travel faster. Using the knowledge on motion, force and the properties of materials, explain the suggestions based on the following aspects:(i) the surface of the board(ii) the shape of the board(iii) material used for the board(iv) material used for the sail(v) the size of the sail

[10 marks]

Modifications Explanation

Smooth // coat with wax 1 Reduce (water) friction / resistance / drag 1

Streamline shape / torpedo / aerodynamic / sharp end / diagramRej: oval

1 Reduce water friction / drag / resistance 1

Low density // strong material // tough // Fiber glass // carbon compositeRej: Hard/Rubber/Glass/Fiber/Composite

1

Easy to float // Not easy to break // Slides faster // Increases the speed // Light // With stand // Small mass

1

Water proof // Low density material // Nylon // Tough // Strong // Canvas // Synthetic

1

To avoid the sail absorbed water // becomes heavier // Not easy to tear off // Small mass // Lighter // Can withstand strong wind without damage

1

Wide // Big // Large 1 Trap more wind // Bigger force 1

Example 3: Q9B SPM 20063. You are given two convex lenses, P and Q, with focal lengths 40 cm and 5 cm respectively. Both the lenses are used to build a simple astronomical telescope at normal adjustment.

Using the two lenses, explain how you are going to build the simple astronomical telescope.

[6 marks]

(ii) Suggest modification that needs to be done on the telescope to produce clearer and bigger images.

[4 marks]- Increases the diameter of the objective lens 1- More light enter the lens 1- Increases the focal length 1- Increase the magnification 1

Questions No. 8 and No.11/No.12 (Making Decision)

Structured:1. Guided decision making2. Follow the instructions in the questions3. Justify your answer with reasons

e

o

ff

Example 1 – Q8 SPM 20091. An eye piece of focal length, fe = 5 cm, and an objective lens are used to build a simple atronomical telescope. The objective lens is chose from Table 1.

Lens Focal length of lens, f0

(cm)

Diameter of the objective lens

(cm)P 10 2 2.5Q 10 2 5.0R 40 8 2.5S 40 8 5.0

Magnification M = F0 / F e (cm)

(i) Complete table 1 by writing down the value of m for every lens.

2, 2, 8, 8[2 marks](ii) Choose the two lenses that produce the

largest image.R, S

[1 mark](iii) Give one reason for the answer in (ii)Largest/Big/Bigger magnification

[1 mark](iv) Chose the two lenses that produce the brightest image

Q, S[1 mark]

(vi) Based on the answer in (ii) and (iv), choose the most suitable lens as the objective lens.

S[1 mark]

(v) Give one reason for the answer in (iv)Largest diameter

[1 marks]

Essay:To answer this question “ explain the suitability of each characteristics and determine the most suitable …. .”, identify 4 different characteristics from the given diagrams or table. The answer in a table form.

Characteristic

Reason

[ ] is chosen. Reason : It has …...

Common mistakes1. Elaborate all characteristics2. Rewrite the value of characteristic given without stating low or high3. Does not state all characteristics/ reasons after making a justification

1. Question will state the characteristics in the form of diagram or table. Study the characteristics carefully2. Choose the suitable characteristics according to the need of the question. Use the word low or high3. Make a ranking based on chosen characteristics4. Make a justification5. State the reason

Example – Q11C SPM 20081. Diagram 11.1 shows a light signal travelling through an optical fibre made of glass.

(a) The optical fibre in Diagram above can be used in telecommunications and medicine. You are asked to investigate the characteristics of optical fibres for use in these fields as shown in Table 11.

Explain the suitability of each feature of optical fibre in Table 11 for use in telecommunications and medicine. Determine the most suitable optical fibre that is capable of carrying the largest number of signals simultaneously.Give reasons for your choice.

[10 marks]Characteristics Explanation Use a bundle of fine parallel optical fibre 1

Can receive more information 1

Choose η1 > η2 1 Total internal reflection can occur 1

Must be high flexibility 1 So that it can follow the curve path 1

Purity of inner core must be very high 1

So that the signal can travel without losing information // information easy to send 1

R is choose 1

Because it use a bundle of fine parallel optical fibre, η1 > η2 , high flexibility and very high purity of inner core 1

Example 3 – Q12C SPM 2009(a) Your are asked to investigate the design and

the characteristics of five filament lamps shown in diagram 12.

Explain suitability of each characteristic of the lamps and determine the lamp which can produce the brightest light. Give reason for your choice.

[10 marks]

Characteristics Explanation Coil 1 High resistance /

more heat 1

Thin 1 More resistance / more heat 1

Tungsten 1 High melting point / High resistance / Not melt easily 1

Low pressure 1 The bulb will not burst / explode / brake 1

R 1

Coiled, thin wire, tungsten, nitrogen at low pressure 1

(b) Diagram 12.3 shows an energy saving bulb. When it is connected to a 240 V power supply, the bulb produces 10 joules per second of light energy.Calculate

(i) the current flows through the bulb(ii) the heat energy lost in 1 second from the bulb(iii) the efficiency of the bulb

[5 marks ](i) 11/240 1

0.046 A / 0.05 A 1

(ii) 11-10 = 1 J 1

(iii) [10/11] x 100 1

90.91 / 90.909 / 90.9090 1