physics spm forecast papers

20

Click here to load reader

Upload: whywhyq

Post on 28-Nov-2014

261 views

Category:

Documents


15 download

TRANSCRIPT

Page 1: Physics SPM Forecast Papers

1

Instructions: This paper consists of 50 questions. Each question is given choices, A , B, C and D. Choose the most suitable answer. Answer all questions.

(50 marks) Time: 1 hour 15 minutes PAPER 1

1 Which of the following units is not a base unit?A s C gB K D A

2 The graph in Figure 1 shows the relationship between quantities p and q.

b

aq

O

p

Figure 1

A p = b —–a

q + b

B p = b —–a

q + a

C p = – b —–a

q + b

D p = – b —–a

q + a

3 Figure 2 shows a velocity-time graph for a moving object.

v (m s–1)

t (s)O

10

5 15 22

Figure 2

The kinetic energy of the object is constant fromA 0 s to 5 s C 15 s to 22 sB 5 s to 15 s D 0 s to 22 s

4 Which solid would exert the greatest pressure on the ground if all the solids have the same mass? A C

B D

5 A long jumper landed on the sandy ground with his knees bent.

Figure 3

Why did he bend his knees? A To reduce the impulse of his legs on the

ground. B To increase the impulse of his legs on the

ground. C To reduce the impulsive force of his legs on the

ground. D To increase the impulsive force of his legs on

the ground.

6 Figure 4 shows a metal sphere moving on a frictionless rail.

P

QR

S

Figure 4

PHYSICSSPM Forecast Paper

Page 2: Physics SPM Forecast Papers

2

The metal sphere possesses maximum potential energy at the position A P B Q C R D S

7 Figure 5 shows two metal cubes.

1 kg3 kg

cube P cube Q

Figure 5

Which of the following quantities is constant when cubes P and Q are in free fall? A Velocity B Momentum C Acceleration D Gravitational force

8 Figure 6 shows a boy holding a spring balance with a load on it in a stationary lift. The reading of the spring balance is 16 N.

10

20

30

40

50

60

70

Figure 6

What is the reading of the spring balance when the lift moves down with a deceleration of 3 m s–2? A 11.2 N B 16 N C 17.8 N D 20.8 N

9 A ball is dropped from a height in a vacuum cylinder. Which physical quantity of the ball is constant while it is falling? A Momentum B Kinetic energy C Potential energy D Acceleration

10 Figure 7 shows the path of a trolley moving down a smooth rail.

A

BC

Drail

trolley

Figure 7

At which position does the trolley have the greatest kinetic energy?

11 In Figure 8, PQRS is a parallelogram. m, n, and k are three vectors.

QP

Rk

nm

S

Figure 8

Which of the following shows the correct relationship between m, n and k? A n = m + k B m = k + n C k = m + n D m + n + k = 0

12 A long jumper bends his legs while landing on the ground. This action is important because A the jumper can jump further. B the impulsive force acting on the jumper can

be reduced. C the frictional force acting on the jumper can be

reduced. D the collision time between the jumper’s legs

and the ground can be reduced.

13 Figure 9 shows a glass prism.

T

U

Q

R

P

S

10 cm

5 cm

8 cm

6 cm

Figure 9

The prism exerts mininum pressure on a horizontal table if it is resting on the face A PUQ C PQRS B QRTU D PSTU

Page 3: Physics SPM Forecast Papers

3

14 A boy blows into a filter funnel with the polystyrene ball held inside as shown in Figure 10.

filter funnel

polystyrene ball

Figure 10

Which principle explains the diagram? A Pascal’s principle B Archimedes’ principle C Bernoulli’s principle

15 A spring extends 2 cm when subjected to a load of 200 g. The spring is cut into two equal lengths and arranged in parallel to each other. What is the extension of the spring system when subjected to a load of 300 g? A 0.75 cm C 2.00 cmB 1.50 cm D 2.25 cm

16 Figure 11 shows a cross section of a pool.

3 m

2 m

5 m

waterP

Q4 mR

Figure 11

What is the difference in water pressure between points P and Q? [Density of water = 1000 kg m–3] A 2.0 × 104 Pa B 3.0 × 104 Pa C 4.0 × 104 Pa D 5.0 × 104 Pa

17 Figure 12 shows a test tube with some ball bearings floating upright in water.

ball bearing

water

test tube

Figure 12

Which of the following gives the correct relationship between the physical quantities in the situation above?

A Upthrust = Weight of test tube + Weight of ball bearings

B Upthrust > Weight of test tube + Weight of ball bearings

C Volume of water displaced = Volume of test tube

D Volume of water displaced > Volume of test tube

18 A boy running at 5 m s–1 jumps onto a stationary skateboard as shown in Figure 13.

v m s–1

skateboard

Figure 13

The possible value of v is A greater than 5 m s–1 B equal to 5 m s–1 C less than 5 m s–1

19 A wooden block is placed on an inclined plank as shown in Figure 14. The frictional force acting on the block is 3 N.

30°weight = 10 N

F

plank

Figure 14

What is the minimum force, F, required to maintain the block in equilibrium?A 2 N C 5 NB 3 N D 7 N

20 Figure 15 shows a manometer measuring the pressure of a gas. The difference between the mercury levels is 3 cm.

gas3 cm

mercury

Figure 15

What is the pressure of the gas, in cm Hg? [Atmospheric pressure = 76 cm Hg] A 73 C 79B 76 D 82

Page 4: Physics SPM Forecast Papers

4

21 The boiling point of pure water at the summit is less than100 °C. It is due to A the lower temperature at the summit. B the lower atmospheric pressure at the summit. C the windy condition at the summit.

22 1.5 kg of iron is cooled from 360 °C to 200 °C. How much heat has been released from the iron? [Specific heat capacity of iron = 460 J kg–1 °C–1] A 100.4 kJ B 101 kJ C 105.5 kJ D 110.4 kJ

23 In Figure 16, an observer cannot see the coin in an empty cup but he can see the coin when the cup is filled with water.

coin

Figure 16

The phenomenon of light involved in this situation is A reflection B diffraction C interference D refraction

24 Figures 17 (a) and (b) show incident rays of light travelling to liquid X and liquid Y.

air

liquidX

50º

θ1

air

liquidY

50º

θ2

(a) (b)

Figure 17

If θ1 > θ2, then A refractive index of liquid X = refractive index of

liquid Y B refractive index of liquid X < refractive index of

liquid Y C refractive index of liquid X > refractive index of

liquid Y

25 Figure 18 shows a pencil placed in front of a convex mirror with focal length of 5 cm.

O F C10 cm

convex mirror

Figure 18

The characteristics of the image formed are A virtual, upright, larger than object. B virtual, upright, smaller than object. C real, inverted, larger than object. D real, inverted, smaller than object.

26 Figure 19 shows the formation of the image using a convex lens.

50 cm

20 cm image

object

Figure 19

What is the focal length of the lens? A 10 cm C 15 cmB 12 cm D 20 cm

27 Figure 20 shows an incident ray of light travelling into a prism. The critical angle of the prism is 40°.

BC D

PA

50º 50º

80º

Figure 20

In which path does it travel from point P ?

28 Figure 21 shows the distance between the object and its image in a liquid.

image

object

liquid

6 cm

Figure 21

If the refractive index of the liquid is 1.4, what is the real depth of the liquid? A 8.4 cm C 18.0 cmB 9.8 cm D 21.0 cm

Page 5: Physics SPM Forecast Papers

5

29 Figure 22 shows the side view of a ripple tank in which the depth decreases towards both sides. G is an iron bar that vibrates at a constant frequency.

G

Figure 22

Which pattern of the wavefronts will be observed in the ripple tank? A

B

C

D

30 A set of plane waves is produced in a ripple tank. The period of the waves is T seconds. A cork is placed in the tank. What is the time taken for the cork to move from the crest to the trough?

A T —–8

D T —–2

B T —–6

C T —–4

31 Which of the following waves is a longitudinal wave? A Radio waveB X-raysC Sound waveD Visible light

32 In a Young’s double-slit experiment, blue fringes are formed on the screen when a blue light source is used. The experiment is repeated using a red light. What is the ratio of the distance between two consecutive blue fringes to that of red fringes? [Wavelength of red light = 7 × 10–7 m and wavelength of blue light = 4.5 × 10–7 m] A 0.64 B 0.90 C 1.25 D 1.43

33 Figure 23 shows the wavefronts of a plane wave moving towards a gap.

Figure 23

Which statement is correct about the waves going through the gap? A The frequency of the waves becomes lower. B The wavelength of the waves becomes longer. C The speed of the waves remains constant.

34 Figure 24 shows an interference pattern of two coherent water waves.

R P

Q

troughcrest

Figure 24

The constructive interference occurs at A P and Q C Q and R B P and R D P, Q and R

35 Figure 25 shows a current-carrying straight wire, PQ in a magnetic field.

QW

V

N S

P

I Y

X

Figure 25

The wire experiences a force in the direction A V C X B W D Y

36 Four circuits A, B, C and D have three identical resistors respectively. A

B A

A

Page 6: Physics SPM Forecast Papers

6

C

D

A

A

Which circuit records the highest ammeter reading?

37 Figure 26 shows an insulated wire wound on a soft iron core and connected to a battery.

X Y

Figure 26

Pole at X Pole at Y

ABCD

North South North South

NorthNorthSouthSouth

38 Figure 27 shows the wave form of an alternating current on the screen of a cathode-ray oscilloscope. The timebase is set to 5 milliseconds per centimetre.

1 cm

1 cm

Figure 27

What is the frequency of the alternating current? A 15 Hz C 25 Hz B 20 Hz D 50 Hz

39 Figure 28 shows an alternating current source connected to a transformer, two diodes and a cathode-ray oscilloscope (CRO).

CROR

Figure 28

The display shown on the screen of the CRO is A C

B D

40 Figure 29 shows a transistor circuit.

X

Y

2 k

Figure 29

Which of the following are component X and component Y ?

Component X Component Y

A

B

C

D

41 An ideal transformer has the same value of a quantity in both the primary and secondary coils. The quantity is A current B power C potential difference D number of turns of coils

42 Which of the following figures gives the greatest deflection of the galvanometer? A

B S

G

4 m s–1

N

N

G

2 m s–1

S

Page 7: Physics SPM Forecast Papers

7

C

D

43 Table 1 shows the truth table of a logic gate.

Input Output

P Q R

0 0 0

0 1 1

1 0 1

1 1 0

Table 1

The symbol for the logic gate which gives the above truth table is A

B

C

D P

Q

R

P

Q

R

P

Q

R

P

Q

R

44 Figure 30 shows the circuit for a combination of logic gates.

X

PQ

Figure 30

If the inputs P and Q are 1011 and 0101 respectively, then the output X is A 1010 C 0111 B 1100 D 1110

45 A telescope consists of two convex lenses of power 10 D and 4 D. What is the distance between the lenses in normal adjustment? A 10 cm C 15 cm B 14 cm D 35 cm

46 Figure 31 (a) shows air trapped in an airtight cylinder.

air

(a) (b)

airtightpiston

load

Figure 31

When a load is put on the piston as shown in Figure 31 (b), the quantity which remains constant in the trapped air isA density B volume C massD pressure

47 Nucleus mn X has k neutrons.

The value of k is A m B n C m – n D m + n

48 A radioactive sample has an initial activity of 3600 disintegrations per minute. After two hours, its activity decreases to 225 disintegrations per minute. What is the half-life of the radioactive sample? A 60 minutes B 40 minutes C 30 minutes D 24 minutes

49 Thermionic emission is the process of A emission of electrons from a hot metal surface.B deflection of electron beam from the Y-plates. C accelerating electrons from cathode to anode. D emitting light when electrons collide with a

fluorescent screen.

50 Figure 32 shows the shooting marks on a target.

A B C

Figure 32

Among the participants A, B and C, which participant is consistent but not accurate?

S

4 m s–1

G

N

N

G

2 m s–1

S

Page 8: Physics SPM Forecast Papers

8

1 Figure 1.1 shows a micrometer screw gauge used to measure the diameter of a wire.

P

wire

Figure 1.1

(a) (i) Name the part labelled P. [1 mark] (ii) State the function of P. [1 mark] (b) The diameters of the wire at three different places are shown in Table 1.1.

Table 1.1

Diameter, d (mm)

1 2 3

3.21 3.20 3.22

(i) Why is the diameter measured three times? [1 mark] (ii) The measurements are consistent. What does it mean? [1 mark]

2 Figure 2.1 shows light from the same source passing through two narrow slits which are close together. They emit a coherent light wave. Vertical bright and dark lines are formed on the translucent screen at a distance 3.0 m in front of the double slit.

3.0 m

verticalbright anddark lines

translucentscreen

verticaldouble slit

lightsource

Figure 2.1

(a) The bright vertical lines are due to the constructive interference of the light waves. State how constructive interference occurs. [1 mark]

(b) Given that the slit separation is 0.5 mm and the distance between 11 bright vertical lines is 4.0 cm, calculate the wavelength of the light source used. [2 marks]

(c) What will happen to the distance between two bright lines if the slit separation is decreased? [1 mark]

3 Figure 3.1 shows a block P immersed in boiling water for a long time and then transferred into beaker X. The mass of water in beaker X is 0.2 kg at 25 °C.

P

boilingwater

beaker

water

X

Figure 3.1

Instructions: Answer all questions in this section. The suggested time to complete this section is 90 minutes.

Section A (60 marks) Time: 2 hours 30 minutes PAPER 2

Page 9: Physics SPM Forecast Papers

9

Specific heat capacity of P = 900 J kg–1 °C–1 Specific heat capacity of water = 4200 J kg–1 °C–1 (a) (i) What is the initial temperature of the block P ? [1 mark] (ii) Give a reason for your answer in (a)(i). [1 mark] (b) (i) Calculate the rise in temperature of water in the beaker X if the block P releases 12 kJ of heat energy.

[2 marks] (ii) Calculate the mass of P. [2 marks]

4 Figure 4.1 shows student A standing on a weighing scale in a lift with a friend standing beside her. The effect of the movement of the lift on the readings of the weighing scale was observed by her friend. The mass of the student A is 60 kg. (a) What is the weight of the student A? [1 mark] (b) State three types of possible movement of the lift when the

reading of the weighing scale is 60 kg. [3 marks] (c) (i) State the type of movement of the lift which involves a

physical quantity when the reading of the weighing scale is 54 kg. [1 mark]

(ii) Find the value of the physical quantity as in (c)(i). [2 marks]

5 Figure 5.1 shows the image of a black line when viewed through a piece of glass with a focal length of 10 cm.

Figure 5.1

(a) State the light phenomenon that causes the image of the line to be diminished. [1 mark] (b) (i) Name the type of lens used in Figure 5.1. [1 mark] (ii) Given that the distance between the lens and the black line is 8 cm, calculate the distance of the

image from the lens. [3 marks] (c) Sketch a ray diagram to show how the image is formed. [3 marks]

6 Figure 6.1 shows a spring balance supporting a piece of stone immersed in a beaker of water. The reading of the spring balance is 2.0 N.

stonewater

beaker

string

spring balance

Figure 6.1

weighing scale

friendstudent A

lift

Figure 4.1

Page 10: Physics SPM Forecast Papers

10

(a) What is the resultant force acting on the stone as shown in Figure 6.1? [1 mark] (b) (i) Name three forces that act on the stone. [2 marks] (ii) State the relationship of the three forces in (b)(i). [1 mark] (c) Which of the three forces gives the reading of the spring balance? [1 mark] (d) (i) What will happen to the reading of the spring balance if the water is replaced with a brine solution?

[1 mark] (ii) Explain your answer in (d)(i). [3 marks]

7 A machine has a green lamp, a red lamp and a buzzer. The green lamp is on when the machine is operating normally. If a fault is detected, the green lamp is off, while the red lamp and the buzzer are on. When an operator acknowledges the fault by pressing a red button, the buzzer stops but the red light stays on.(a) Complete the truth table in Table 7.1 to show the function of the machine.

Table 7.1

Input Output

Fault Red button Green lamp Red lamp Buzzer

0 0

0 1

1 0

1 1

[4 marks] (b) Based on the truth table in Table 7.1 for the output of the green lamp, complete the logic circuit in Figure

7.1, by using one AND gate, one NOT gate and one OR gate [ignore the outputs for the red lamp and the buzzer].

Green lamp

Fault

Red button

Figure 7.1

[6 marks]

8 Figure 8.1 shows an electric iron with specification 120 V, 1.1 kW.

to power supply

Figure 8.1

(a) What is meant by specification 120 V, 1.1 kW ? [1 mark] (b) The iron is connected to a 120 V supply. Calculate (i) the current passing through the iron, [2 marks] (ii) the resistance of the iron. [2 marks] (c) What will happen to the power of the iron if it is connected to a power supply of 240 V ? Determine the value of the new power (assuming the resistance of the heating element does not depend

on temperature). [3 marks] (d) If the iron is to maintain its power of 1.1 kW, a resistor with resistance R’ is to be connected to the iron. (i) State the value of R’. (ii) Suggest how you would connect the resistor to the iron. [3 marks]

Page 11: Physics SPM Forecast Papers

11

(e) Table 8.1 shows the power rating of appliances used in the home.

Table 8.1

Appliances Power rating, P (W)

Shower heater 3000

Television 250

Kettle 2500

Hairdryer 1200

If all the appliances are used for the same length of time, state which one would cost the most to run. [1 mark]

Section B (20 marks)Instructions: Answer any one question from this section. The suggested time to answer this section is 30 minutes.

9 Figures 9.1 and 9.2 show the parallel rays of light directed toward a curved mirror P and a lens Q. F is the focal point.

F

curved mirror P

F

lens Q

Figure 9.1 Figure 9.2

(a) (i) Name the curved mirror in Figure 9.1. [1 mark] (ii) What is meant by focal point of the curved mirror? [2 marks] (b) Using Figures 9.1 and 9.2, compare the effects of the curved mirror and the lens on the light rays and the

characteristics of the image formed. [5 marks] (c) Explain an application of the curved mirror in Figure 9.1. [2 marks] (d) You are given two pieces of 45° right-angled glass prisms. Describe how you would make a periscope.

[10 marks]

10 Nuclear energy is the energy released during the process of a nuclear fusion or nuclear fission. Nuclear fission: Uranium-235 + neutron → Barium-141 + Krypton-92 + 3 neutrons + energy 235.044 a.m.u. 1.009 a.m.u. 140.914 a.m.u. 91.898 a.m.u. 3.027 a.m.u.

Nuclear fusion: Hydrogen-2 + Hydrogen-2 → Helium-3 + neutron + energy 2.015 a.m.u. 2.015 a.m.u. 3.017 a.m.u. 1.009 a.m.u.

(a) (i) What is meant by nuclear fusion? [2 marks] (ii) Based on the equations of reaction and information given above, compare nuclear fusion and nuclear

fission. [5 marks] (b) Describe how a chain reaction takes place in a nuclear fission of uranium-235. [5 marks] (c) There are many uses for radioisotopes in medicine. Using your knowledge on radioactivity, explain the uses

of radioisotopes in (i) diagnosis [6 marks] (ii) therapy [2 marks]

Page 12: Physics SPM Forecast Papers

12

Section C (20 marks)Instructions: Answer any one question from this section. The suggested time to answer this section is 30 minutes.

11 Figure 11.1 shows a ship which has dropped its anchor over its side in order to prevent it from moving. Another interesting feature of the ship is the lifeboats attached to its side. (a) How can a huge and heavy ship float on the sea?

[6 marks](b) Table 11.1 shows the characteristics of materials which can

be used to make anchors and lifeboats. You are asked to investigate the characteristics of the

materials in Table 11.1 which could be used to make an anchor and a lifeboat.

Table 11.1

Characteristics Materials

Density (kg m–3) State Nature (Hardness)

P 2800 Metal Medium

Q 1200 Non Metal Hard

R 3600 Metal Hard

S 760 Non Metal Medium

T 13 600 Liquid Soft

Explain the suitability of each characteristic in Table 11.1 and hence determine which material is most suitable to be used to make the anchor. Do the same for the lifeboats. Justify your choice. [10 marks]

(c) A boat of mass 5 × 105 kg floats on sea water of density 1030 kg m–3. Calculate the volume of sea water displaced. [4 marks]

12 Table 12.1 shows five ideal transformer circuits P, Q, R, S and T. The input voltage for all the circuits is 240 V alternating current.

Table 12.1

Transformer circuit

Input voltage, Vp (V)

Number of turns of coilRectification Capacitor

Primary, Np Secondary, Ns

P 240 a.c. 4000 200 Without With

Q 240 a.c. 100 2000 Without Without

R 240 a.c. 4800 400 With Without

S 240 a.c. 4000 200 With With

T 240 a.c. 2000 100 With Without

(a) (i) Explain the meaning of rectification. [2 marks] (ii) What is the function of the capacitor in the circuit? [1 mark] (iii) Explain the efficiency of a practical transformer. [4 marks] (b) Based on the information given in Table 12.1, which of the circuits is suitable to run a radio of 12 V d.c.?

[10 marks] (c) A transformer has 10 000 turns on its secondary coil and 100 turns on its primary coil. An alternating

current of 10 A flows in the primary coil when it is connected to a 24 V a.c. supply. What is the maximum current that could flow in the secondary coil if the transformer is 90% efficient? [3 marks]

Figure 11.1

Page 13: Physics SPM Forecast Papers

13

Section A (28 marks) Time: 1 hours 30 minutes PAPER 3Instructions: Answer all questions in this section. The suggested time to complete this section is 60 minutes.

1 A student carries out an experiment to study the relationship between the resistance, R and the diameter, d of a coil. A 1.5 m length of constantan wire is used. A coil of 10 turns is wound on a glass rod before connecting to the circuit with crocodile clips as shown in Figure 1.1.

A

V

3.0 V switch

rheostat

10 turns

d

constantan coil

Figure 1.1

The turns are close to but not touching each other. An adhesive tape is used to stick the turns to the glass rod. The rheostat is adjusted so that the current flow is 0.5 A. The reading on the voltmeter, V is read. V

The diameter, d of the coil is measured and the resistance, R of the coil is calculated from R = V —–I

.

The above procedure is repeated by winding the wire on glass rods of different diameters. The actual sizes of the coils and the corresponding values of V are shown in Figures 1.2, 1.3, 1.4, 1.5 and 1.6.

Figure 1.2 Figure 1.3 Figure 1.4

Figure 1.5 Figure 1.6

V = 1.00 V

d

V = 1.40 V V = 1.80 V

V = 2.20 V V = 2.50 V

Page 14: Physics SPM Forecast Papers

14

(a) Based on the experiment described, identify (i) the manipulated variable, [1 mark] (ii) the responding variable, [1 mark] (iii) a fixed variable. [1 mark] (b) Use a metre rule to measure the diameters, d of the coil. V

Calculate the corresponding resistances, R from R = V —–I

.

Tabulate the values of d, V, I and R. [7 marks] (c) Draw a graph of R against d on a graph paper. [5 marks](d) Use your graph to state the relationship between R and d. [1 mark]

2 A student carried out an experiment to investigate the relationship between the reading of the volume of water in a measuring cylinder and the number of steel spheres used for displacing the water to determine the radius of the sphere. The student used 25 steel spheres of the same size. The spheres were dropped into the measuring cylinder to displace the water in the cylinder upwards. The results of the experiment are shown in the graph V against n in Figure 2.1.

5

5

O

10

15

20

25

10 15 20 25 30n

30

35

V (cm3) Graph V against n

Figure 2.1

(a) State the relationship between V and n. [1 mark] (b) Using the graph, determine the volume of water, V o before any sphere is dropped into the measuring

cylinder. Show on the graph how you obtained your answer. [2 marks] (c) (i) Calculate the gradient, k, of the graph of V against n. Show on the graph how you determined k.

[3 marks] (ii) The gradient, k represents a physical quantity. Name the physical quantity. [1 mark] (d) (i) From the graph of V against n, determine the number of spheres, n’ needed to displace 10.0 cm3 of

water. Show on the graph how you obtained your answer. [2 marks] (ii) The radius of the steel sphere used to displace the water is given by the formula:

r = 33k —–4π

Calculate the radius of the sphere. [2 marks] (e) State one precaution that should be taken during this experiment. [1 mark]

Page 15: Physics SPM Forecast Papers

15

Section B (12 marks)Instructions: Answer any one question from this section. The suggested time to answer this section is 30 minutes.

3 Steven and his twin brother who has the same weight as him were in a water park. They slid down two different water slides with different heights as shown in Figure 3.1. Steven hit the water at a further distance and splashed up more water.

Steven

Figure 3.1

Based on the above information and observation; (a) State one suitable inference. [1 mark] (b) State one appropriate hypothesis that could be investigated. [1 mark] (c) With the use of apparatus such as a trolley, a ticker-timer and other apparatus, describe an experiment

framework to investigate the hypothesis stated in 3(b). In your description, clearly state the following: (i) aim of the experiment, (ii) variables in the experiment, (iii) list of apparatus and materials, (iv) arrangement of the apparatus, (v) the procedure of the experiment, which includes the method of controlling the manipulated variable

and the method of measuring the responding variable, (vi) the way you would tabulate the data, (vii) the way you would analyse the data. [10 marks]

4 A student throws a stone into a lake with depth of water increasing towards the centre of the lake as shown in Figure 4.1. The wave pattern formed is as shown in Figure 4.2.

stone

shore

lake-bed

wavefront

Figure 4.1 Figure 4.2

Based on the above information and observations; (a) State one suitable inference. [1 mark](b) State one appropriate hypothesis that could be investigated. [1 mark](c) With the use of apparatus such as a ripple tank and other apparatus, describe an experiment framework to

investigate the hypothesis stated in 4(b). In your description, clearly state the following: (i) aim of the experiment, (ii) variables in the experiment, (iii) list of apparatus and materials, (iv) arrangement of the apparatus, (v) the procedure of the experiment, which includes the method of controlling the manipulated variable

and the method of measuring the responding variable, (vi) the way you would tabulate the data, (vii) the way you would analyse the data. [10 marks]

Page 16: Physics SPM Forecast Papers

16

ANSWERS

Paper 1 1 C 2 C 3 B 4 C 5 C 6 A 7 C 8 D 9 D 10 C 11 A 12 B 13 B 14 C 15 A 16 B 17 A 18 C 19 A 20 C 21 B 22 D 23 D 24 B 25 B 26 B 27 A 28 D 29 B 30 D 31 C 32 A 33 C 34 B 35 B 36 B 37 A 38 D 39 C 40 D 41 B 42 D 43 D 44 D 45 D 46 C 47 C 48 C 49 A 50 B

Paper 2Section A 1 (a) (i) Ratchet knob

(ii) Ratchet knob is used to prevent the user from exerting undue pressure on the wire.

(b) (i) The repeated measurements are to ensure the consistency of the measurements.

(ii) It means the measured values are close to each other with little or no deviation amongst them.

2 (a) Constructive interferences occur when the crests of two waves from the slits coincide. Constructive interferences also occur when the troughs of two waves coincide.

(b) D = 3.0 m a = 0.5 mm = 5 × 10–4 m

x = 4 cm———10

= 0.4 cm = 4 × 10–3 m

Wavelength, λ = ax—–D

= (5 × 10–4 m)(4 × 10–3 m)————————————

3.0 m = 6.7 × 10–7 m(c) The distance between two bright lines increases.

3 (a) (i) 100 °C (ii) Block P is in thermal equilibrium with

boiling water at 100 °C(b) (i) Q = mcθ 12 000 J = (0.2 kg)(4200 J kg–1 °C–1)(θ) θ = 14.3 °C (ii) Q = mcθ 12 000 J = m × 900 × (100 – 39.3) ∴ m = 0.22 kg

4 (a) Weight, W = mg = (60 kg)(10 N kg–1) = 600 N

(b) • The lift is stationary. • The lift is moving up with uniform velocity • The lift is moving down with acceleration, a(c) (i) The lift is moving down with acceleration,

a. (ii) R = 54 kg × 10 N kg–1

= 540 N mg – R = ma 600 – 540 = 60a a = 1 m s–2

5 (a) Refraction of light.(b) (i) Concave lens (ii) Focal length, f = –10 cm Object distance, u = 8 cm

1—u

+ 1—v

= 1—f

1—8

+ 1—v

= 1— —

–10

1—v

= 1— —

–10 –

1—8

v = –4.4 cm Image distance is 4.4 cm on the same side

as the black line.(c)

F

concavelens

F = Focal point

O = Object

I = Image

O I vu

f

6 (a) Resultant force acting on the stone = 0 (as it is in equilibrium)(b) (i) • Force of gravity or weight • Buoyant force • Tension in the string (ii) Fx + Fy = Fz

(c) Fx

(d) (i) Reading of spring balance will decrease. (ii) The buoyant force equals to ρVG where ρ

is the density of the liquid. As ρ (brine solution) is greater than water, the buoyant force is greater, thus reducing the tension in the string.

Page 17: Physics SPM Forecast Papers

17

7 (a) Input Output

FaultRed

buttonGreen lamp

Red lamp

Buzzer

0 0 1 0 0

0 1 1 0 0

1 0 0 1 1

1 1 0 1 0

(b)

AND

OR

NOTFault

Red button

Green lamp

8 (a) The iron will release 1.1 kJ of heat energy per second when it is connected to a 120-V power supply

(b) (i) P = VI

I = P—V

= 1100 W————120 V

= 9.2 A

(ii) P = V 2— –R

R = V 2— –P

= 1202

——–1100

= 13.1 Ω

(c) The power of the iron will increase.

P = V 2— –R

= 2402

——–13.1

= 4.4 kW

(d) (i) 13.1 Ω (ii) The resistor is connected in series with the

iron (both have the same resistance, so the voltage across each component is 120 V).

(e) Shower heater

Section B 9 (a) (i) Convex mirror.

(ii) Focal point of a curved mirror is the point on the principal axis to which all rays originally parallel and close to the principal axis converge, or from which they appear to diverge, after reflection from the mirror.

(b) Parallel rays of light appear to diverge from the focal point F after reflection from the mirror. Parallel rays of light appear to diverge from the focal point F after refraction from the lens. Since the reflected rays from the curved mirror and the refracted rays from the lens are diverging, therefore, the image form is virtual, upright and diminished.

(c) Convex mirrors are used as rear view mirrors in vehicles, since they are always give an erect image and a wider field of view. Convex mirror has a wider field of view than a plane mirror of the same size.

(d)

glass prism

total internalreflection

object

imageeye

Periscope can be made by using two 45° right-angled prisms as shown in the above figure. Light rays from object enter the faces of the prisms normally and fall on the hypotenuse face internally at an angle of incidence of 45°. Total internal reflection occurs here, since the critical angle for a glass is 42°. The image formed is upright and has the same size as the object. The prism periscope produce a single bright and clear image as the image is formed by total internal reflection of light. Prism periscope can be used to view objects behind obstacles. In submarines, periscopes are used to observe ships on the surface of the sea.

10 (a) (i) Nuclear fusion is a type of nuclear reaction in which atomic nuclei of low atomic number fuse to form a heavier nucleus with the release of large amounts of energy.

(ii) Nuclear fusion involves fusion of light nuclei to form heavier nucleus. Nuclear fission involves breaking up of a large nucleus to form lighter nuclei. Both processes produce loss in mass, i.e. mass defect. Both processes release large amounts of energy. In both process, the release of energy is due to mass defect, based on the formula, E = mc 2.

(b)

neutron

uranium-235barium-141krypton-92

Page 18: Physics SPM Forecast Papers

18

When uranium-235 is bombarded by a neutron, it forms uranium-236, which is unstable and breaks down, splitting into barium-141, krypton-92 and three neutrons, as shown in the above figure. The three neutrons are slowed down to produce further fission by colliding with other uranium-235 nuclei to generate more fission. This sets up a chain reaction and leads to release of very large amounts of energy. The mass of uranium-235 must be more than the critical mass. Critical mass is the minimum mass of a fissile material that will sustain a chain reaction.

(c) (i) A radioisotope and a stable isotope of the same element have exactly the same chemical properties and they form the same compounds. For example, the radioisotope

Sodium-24 forms sodium chloride molecules of the same chemical properties. Salt of Sodium-24 can be used as tracer which can be followed wherever it goes. If a patient takes in some of this Sodium-24 tracer, its progress through the body can be followed by a Geiger-Muller tube or othe radiation detector moved over the body of the patient to show where the Sodium-24 reached and how much of it has been absorbed. This is because Sodium-24 decays by emitting yyy-rays which pass out of the body to be detected.

(ii) A nuclide of Cobalt-60 is widely used to give patients a large dose of yyy-rays for the treatment of cancers. A restricted beam of yyy-rays is carefully directed at the cancer site from an external Cobalt-60 source during radiotherapy.

Section C 11 (a) According to Archimedes’ principle, when a body

is partially or completely immersed in a fluid, the buoyant force acting on the body is equal to the weight of fluid displaced.

The two forces acting on the floating ship, i.e., the weight of the ship and the buoyant force are in equilibrium.

The buoyant force is equal to the weight of the sea water displaced by the ship.

The heavy and huge ship can float because the buoyant force acting on it is equal and opposite to the weight of the ship.

(b) The anchor must have a high density so that it can sink easily in the sea. Anchor is made of metal that is very hard in nature so that it can withstand rough use and very rough seabed. The material suitable for making the anchor is R, because R is a very dense metal and it is hard in nature. Life-boat must be able to float

easily on the sea water, so it must be made of material of lower density than sea water. It is made of non-metal so that it is light weight. Life-boat is made of medium soft material so that it safe when it knocks into something or people. The material suitable for making life-boat is S because it is of low density, it is a non-metal and of medium hardness.

(c) Weight of sea water displaced = Weight of the boat ρVg = 5 × 105 kg × 10 N kg–1

= 5 × 106 N Volume of sea water displaced, V

= 5 × 106 N————————————

(1030 kg m–3)(10 N kg–1)

= 485.4 m3

12 (a) (i) Rectification is the process of obtaining a direct current from an alternating electrical supply. Rectification consists of half-wave rectification and full-wave rectification.

(ii) Capacitor provides the extra energy needed to keep the power output constant at its peak value. Capacitor is used to smooth the output of the transformer.

(iii) All pratical transformers waste some energy because of heating effects in the core and coils. It means that the power output is less than the power input. The two main factors affecting the efficiency of a pratical transformer are:• the coils have resistance and heat up.

Thick copper wire of low resistance is used to make the primary and secondary coils.

• the changing magnetic field in the core induces eddy currents which produces heat. The core is laminated with insulated sheets of iron to reduce the eddy current.

(b) • It must have a step-down transformer so as to step-down voltage from 240 V to 12 V.

• The transformer must have the ratio Np : Ns = 20 : 1 so as to produce an voltage output of 12 V.

• It must have rectification so that the voltage output is direct current. i.e. 12 V d.c..

• It must have capacitor to produce smoothing effect on the voltage output.

• Circuit S is the most suitable because it has a step-down transformer with Np : Ns = 20 : 1, rectifier and capacitor.

(c) Input power = VpIp = (24 V)(10 A) = 240 W

Vs— –Vp

= Ns— –Np

Page 19: Physics SPM Forecast Papers

19

Vs = 10 000——–—

100 × 24 V

= 2400 V

Efficiency = Power output——–— ——–Power input

× 100 90% =

Power output——–— ——–240 W

× 100

Power output = 216 W VsIs = 216 W

Is = 216 W——–—2400 V

Current output, Is = 0.09A

Paper 3Section A 1 (a) (i) Diameter, d of the coil

(ii) Resistance, R of the coil (iii) Number of turns of the coil or type and

thickness of the wire.

(b) d (cm) I (A) V (V) R (Ω)

1.7 0.50 1.0 2.0

2.2 0.50 1.4 2.8

2.9 0.50 1.8 3.6

3.5 0.50 2.2 4.4

4.0 0.50 2.5 5.0

(c) Graph R against d:

0.5

1

0

2

3

4

5

1.0 1.5 2.0 2.5 3.0 3.5 4.0 d (cm)

R (Ω)

x

x

x

x

x

(d) The resistance, R of the coil is proportional to the diameter, d of the coil.

2 (a) V increases linearly with n.(b)

20

15

10

5

151050

25

30

35

2520 30

V (cm3)

n

From the intercept on the V-axis, Vo = 12.0 cm3

(c) (i) The gradient, k =

33.0 – 16.0——–— ——–20

= 0.85 cm3

(ii) The gradient, k represents the volume of a sphere

(d) (i) n’ = 12 (please refer to the graph) (ii) r = 3

3k —–4π

= 3

3 × 0.85 —–———4π

= 0.588 cm(e) While reading V, the eyes should be at the

same level with the water surface in the measurinng cylinder to avoid parallax error.

Section B 3 (a) Inference:

The velocity of the boys at the lower ends of the water slides is affected by the height of the slide.

(b) Hypothesis: The higher the upper end of the slide, the

greater the velocity at the lower end of the slide.

(c) (i) Aim: To investigate the relationship between the

velocity of an object and the height where it is released.

(ii) Variables: Manipulated variable: Height, h Responding variable: Velocity, v Fixed variable: The inclined angle of the

runway (iii) Appratus and materials: Ticker-timer with accessories, ticker tape,

metre rule and runway (iv) Arrangement of apparatus:

woodenblock

h

v

runway table

ticker tapetrolley

u = o

powersupply

ticker-timer

(v) Procedure: 1 A ticker tape is attached to a trolley and

passed through a ticker-timer connected to a power supply.

2 The trolley is placed at a height, h is measured and recorded.

3 The power supply is turned on and the trolley is released to run down the runway.

4 The velocity of the trolley at the bottom

Page 20: Physics SPM Forecast Papers

20

of the runway is determined using formula

v = Distance travelled in 5 ticks——–— ——–——————

Time for 5 ticks

=

s cm——–—0.1 s

5 The experiment is repeated with different heights of 25 cm, 30 cm, 35 cm annd 40 cm.

(vi) Tabulation of data:

h (cm) v (cm s–1)

20.0 v1

25.0 v2

30.0 v3

35.0 v4

40.0 v5

(vi) Graph velocity against height is plotted.

v (cm s-1)

h (cm)

Conclusion: From the table and the graph, it is found

that the velocity increases with the height. The hypothesis is valid.

4 (a) Inference: The wavelength is affected by the depth of

water.(b) Hypothesis: The greater the depth of water, the longer the

wavelength.(c) (i) Aim: To investigate the relationship between the

wavelength and the depth of water. (ii) Variables: Manipulated variable: Depth of water, d Responding variable: Wavelength, λ Fixed variable: Frequency of the wave (iii) Apparatus and materials: Ripple tank with accessories, Xenon

stroboscope, white paper and ruler

(iv) Arrangement of apparatus:

to powersupply

rippletank

lamp

rubber band

motor

vibrating bar

waterXenonstroboscope

observer

white paper

(v) Procedure: 1 A ripple tank is set up with uniform

depth of water of 6 mm 2 The vibrating bar is arranged touching

the surface of water 3 The motor is turned on with a suitable

frequency which is fixed throughout the experiment

4 With the help of Xenon stroboscope, the wave is frozen

5 The distance between 11 ripples, s is measured. The wavelength, ooo is determined from the formula:

λ = s— –

10

6 The experiment is repeated with depth of water

d = 8 mm, 10 mm, 12 mm and 14 mm (vi) Tabulation of data:

d (mm) λ (cm)

6 λ1

8 λ2

10 λ3

12 λ4

14 λ5

(viii) Graph wavelength, λ against depth, d of water is plotted.

λ (cm)

d (cm)

Conclusion: From the table and the graph, it is found

that the wavelength increases with the depth of water. The hypothesis is valid.