2008 Kedah Spm Physics_ans

4531

SULIT 4531 Physics September 2008

PERSIDANGAN KEBANGSAAN PENGETUA-PENGETUA SEKOLAH MENENGAH NEGERI KEDAH DARUL AMAN

PEPERIKSAAN PERCUBAAN SPM 2008

PHYSICS PERATURAN PEMARKAHAN

Peraturan pemarkahan ini mengandungi

halaman bercetak

4531

PEPERIKSAAN PERCUBAAN SPM 2008

2 KEDAH DARUL AMAN PERATURAN PEMARKAHAN

PHYSICS PAPER Paper 1 Paper 2 Paper 3

MARKS 50 100 40 190

Total

Jumlah markah diskalakan kepada 100% PHYSICS Paper 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

B D B B C B D B C A A D B B C A B D B A A C D D A

26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

PHYSICS

D C A D C C B B C A A C D D D A C C A C A A C C D

3 Paper 2 SECTION A NO. 1 (a) (b) (i)

(ii) (c)

2(a)

(i)

(ii)

(b)

3(a)

(i)

(ii)

(iii)

(c) NO.

MARK SUB TOTAL

State the sensitivity of the metre rule correctly - 0.1 cm

1

State the diameter of five ball bearings correctly - 3.0 cm

1

State the diameter of one ball bearing correctly - 0.6 cm

1

State the instrument correctly - Vernier callipers

1

State the meaning of acceleration correctly - Rate of change of velocity

1

Mark the point correctly - X at the point (5, 30)

1

Show the substitution correctly (10 + 30) 2 Answer with correct unit 40 m

(c)

(b)

MARKING CRITERIA

1 1

Sketch the graph correctly - Curve of the same shape but higher gradient

1

State the principle correctly - Pascal’s principle

1

Answer with correct unit 2.5 N cm-2 // 2.5 x 104 N m-2

1

Compare the pressure correctly - same pressure

1

Show the substitution correctly 2.5 x 5 Answer with correct unit 12.5 N State the reason correctly - Liquid cannot be compressed easily MARKING CRITERIA

4

5

1 1

1

6

MARK SUB TOTAL

4 4(a) (b)

(i) (ii)

(c)

(i) (ii)

Name the principle correctly - Thermionic emission

1

Describe the motion correctly - Uniform acceleration

1

Describe the motion correctly - Uniform velocity

1

State the correct answer - Alternating current

1

Calculate the period correctly T = 3 x 0.02 = 0.06 s State the frequency and unit correctly f = = = 16.7 Hz

1 1

(iii)

5(a)

(i) (ii)

(b)

(i)

(ii)

Sketch the waveform correctly - Sinusoidal with one complete cycle

1

Name the force correctly - Gravitational force / Gravity / Weight

1

Name the type of motion correctly - Free fall

1

Compare the force on the coconuts correctly - In Diagram 5.1, the force is higher/greater // vice versa

1

Compare the change in momentum correctly - The change in momentum is the same for both diagrams.

1

Compare the time of impact between the coconuts and their landing ground correctly - In Diagram 5.1, the time of impact is shorter // vice versa

7

(iii)

(c) (d) (e)

NO.

Relate the force and the time of impact correctly - The shorter the time of impact, the greater the force Name the force correctly Impulsive force State the field event correctly - High jump / Long jump / Triple jump

MARKING CRITERIA

1

1 1 1

8

MARK SUB TOTAL

5 6(a)

(i) State the happening of the wave correctly

Wave diffracts / spreads to a bigger area

1

(ii) State the change to the amplitude of the wave and the reason correctly

-Amplitude of the waves decrease -Energy decreases (iii) State the phenomenon correctly Diffraction (iv) State the change to the speed of the wave correctly Unchanged / same (b)

(c) 7(a)

(i) State the correct situation at P Vibrates/Oscillates (ii) State the correct situation at Q Stationary Name the phenomenon correctly reflection

1 1

1 1

1

8

(i) State the meaning of heat correctly - The energy transferred from a hot object to a cold object // the energy transfer because of the difference in temperature (ii) Explain how the heat is removed correctly

(b)

1 1

1

- The temperature of the forehead is higher than the temperature of the pad

1

- Heat is transferred from the forehead to the pad

1

Show the temperature change correctly 36 – 15

1

Show the correct substitution

(c)

Q = 30 × 4.3 × (36 – 15)

1

Answer with correct unit 2709 J

1

Give suggestion 1 correctly - Increase the mass of the gel

1

Give reason 1 correctly - The heat removed increases with the mass of the gel // the heat removed is directly proportional to the mass

1

Give suggestion 2 correctly - Use a gel with higher specific heat capacity

1

Give reason 2 correctly - The heat removed increases with the specific heat capacity of the gel // the heat removed is directly proportional to the specific heat capacity of the gel NO.

MARKING CRITERIA

1

10

MARK SUB TOTAL

6 8(a)

(b)

(i) (ii) (iii)

State the law correctly - current flowing through a conductor is directly proportional to the potential difference across its ends (provided that its temperature and the other physical conditions remain constant)

1

State that the Ohm’s law is not obeyed - Ohm’s law is not obeyed

1

State the reason correctly - The resistance of the conductor is extremely high

1

Show the method to obtained the current - From the graph, when V = 2.0 V, I = 4.6 x10-3 A Correct answers with unit R= = = 434.8 Ω

1

1 (c)

(i)

(ii)

Match the answers correctly - X with K - Y with M - Z with L Give the reasons correctly - Gradient of the graph represents the effective resistance of the circuit - Series circuit has higher resistance // Parallel circuit has lower resistance

(iii)

1 1 1

1 1

Show the method correctly R = Gradient of graph P = 1 Answer with correct unit = 3Ω

SECTION B

1

12

7 NO 9(a)

MARKING CRITERIA (i) State the light phenomenon correctly - Total internal reflection (ii) State the function of objective lens correctly - used to produce a real, inverted and magnified image // intermediate image State the function of eyepiece correctly - as a magnifying glass (iii) State two advantages of using fibre optics correctly - can carry large amount of data/information - transmit signals with very little loss - can transmit large amount of signals at one time - very much thinner and lighter

(b)

(i) Compare the size of object and the size of image correctly - in diagram 9.2/9.3 the size of object is equal to the size of image (ii) Compare the object distance and the image distance correctly - in diagram 9.2/9.3 the object distance is equal to the image distance

(c)

(i) Compare the focal lengths correctly - Focal length of lens X is shorter than the focal length of Y

MARK SUB TOTAL 1

1

1

1

2

1 1

2

1

1

2

1

(ii) Compare the thickness of lens correctly - Lens X is thicker than lens Y (iii) Relate the focal length to the thickness correctly - The thicker the lens, the shorter the focal length (d)

(i) Draw the ray diagram of a compound microscope correctly T R Eye

Object Fo

Image2

Fe

1

1

3

8 -

R as an eye piece and T as an objective lens Fe and Fo are not overlapped Light rays to form first image First image formed shown Light rays to form final image Final image formed shown

1 1 1 1 1 1

State the characteristics of final image correctly Virtual, magnified and inverted

(Any two) (ii) Suggestion on the modification to produce bigger image By using more powerful // shorter focal length lenses Suggestion on modification to produce brighter image By using a plane mirror near the object to reflect more rays / a lamp near the object/ Objective lens of bigger diameter

2

8

1

1

2 20

10(a)

State the meaning correctly - Isotopes of an element are atoms having the same proton number but different neutron number.

(b)

(i)

1

State the use correctly - to record the radiations detected by the G-M tube

(c)

1

State the use correctly - to detect radioactive radiations

(ii)

1

1

2

Describe the happenings correctly - The isotopes emit radioactive radiations

1

- The original nucleus changes into a different nucleus

1

Name the process correctly - Radioactive decay (disintegration) (d)

1

State the meaning for nuclear fission correctly - The splitting of a heavy nucleus into two lighter nuclei

1

State the meaning for nuclear fusion correctly - The combining of two lighter nuclei to form a heavy nucleus State there is a mass defect after reaction

1

3

9 - The resulting nucleus (nuclei) formed has a smaller mass than the original nucleus (nuclei) State energy released due to mass defect - The mass defect caused energy to be released (resulting in a more stable nucleus /nuclei) (e)

(i)

1

1

4

State how the radioisotope is used - The fertilizer that contains a radioisotope of one of the elements is injected into the soil/plant

1

State a waiting time - Wait for a few days for the fertilizer to be absorbed

1

State the use of the detectors - Use the G-M tube and ratemeter to detect the radiations

1

State how the analysis is done - The locations of where the fertilizer has gone to are located and analysed

(ii)

1

4

State a suitable choice of half-life - The half-life should be a few days long

1

State a reason for the choice of half-life - This allows time for the fertilizer to be absorbed // the effect of the radiation to be minimised

1

State the suitable choice of radiations - The radiation emitted should be beta // gamma radiations

1

State a reason for the choice of radiations - This enables the radiations to penetrate the plant tissue (so that it can be detected)

1

State a suitable choice for the detector - The detector should be able to detect beta // gamma radiations

1

State a reason for the choice of detector - This enables the radiation to be detected

1

6 20

10 SECTION C NO 11(a)

(i)

(ii)

(b)

MARKING CRITERIA State the meaning correctly - Archimedes’ principle states that the buoyant force on an object immersed in a fluid is equal to the weight of fluid displaced by the object. Explain why a balloon filled with helium gas rises up in the air correctly - The balloon acted by two forces: Upthrust and the weight of the balloon - The density of helium gas is less than the density of surrounding air - Upthrust equals to the weight of the air displaced by the ballloon - Upthrust is higher than the weight of the balloon

MARK SUB TOTAL

1

1

1 1 1 1

M1 States a suitable size of the balloon - Large balloon

1

M2 State the reason for M1 correctly - To produce bigger buoyant / upthrust // Increase the volume of the air displaced

1

M3 State a suitable number of the burner - Use 2 burners // Many burners

1

M4 State the reason for M3 correctly - To produce bigger flame // heat up the gas in the balloon faster

1

M5 State a suitable type of fabric of the balloon - Synthetic nylon

1

M6 State the reason for M5 correctly - Light-weight, strong and air-proof material

1

M7 State a suitable temperature of the air in the balloon - High temperature of the air in the balloon

1

M8 State the reason for M7 correctly - Reduce the density /weight of the air in the balloon

1

M9 Choose the most suitable hot air balloon Hot air balloon Q is chosen

1

M10 State the reason correctly Large balloon, use 2 burners / many burners, use synthetic nylon and has high temperature of the air in the balloon // or combination of the reasons

1

4

10

11 (c)

(i)

(ii)

12(a)

(b)

Giving a correct equation Weight = buoyant force / weight of the water displaced

1

Substitute the equation correctly m x 10 = (10 x 2 x 10-6) x 1000 x 10

1

Correct answer with unit m = 0.02 kg /20 g

1

Show a correct substitution 20 = (12 x 2) ρ

1

Correct answer with unit ρ = 0.83 g cm-3

1

5 20

- Current that flows in one direction

1

1

State that the magnets produce a magnetic field - The (magnadur) magnets produce a magnetic field / diagram

1

Defines correctly

State that the current in the wire produces a magnetic field - The current in the wire produces a magnetic field / diagram State that the two fields combine to form a resultant catapult field - The two magnetic fields interact/combine to form a resultant / catapult field / diagram

1

1

Diagram showing the catapult field and the force labelled

S

N

1 (c)

M1 State a suitable density - Low density material

1

M2 State the reason for M1 correctly - Coil has smaller mass / lighter

1

4

12

(d)

M3 State a suitable number of turns - High number of turns

1

M4 State the reason for M3 correctly - Larger force acting on the coil / higher electromagnetic field strength

1

M5 State a suitable strength of magnet - High strength magnets

1

M6 State the reason for M5 correctly - Larger force acting on the coil

1

M7 State a suitable number of segments - More segments

1

M8 State the reason for M7 correctly - Coil rotates smoothly

1

M9 Choose the most suitable motor - Motor R

1

M10 State the reason correctly - Lowest density, high number of turns, high strength magnets and commutator splits into the most number of segments

1

10

(i) Correct expression or answer 3 x 8 // 24 (J)

1

(ii) Correct expression 24 (e.c.f.) 5

1

Answer with correct unit 4.8 W

(iii) Correct expression 4.8 4.8 × 100 // (e.c.f.) 12 12 Correct answer 40% // 0.4

1

1

1

5 20

13 PHYSICS Paper 3 SECTION A NO 1(a)

(i) (ii) (iii)

(b)

(c)

MARK SUB TOTAL

MARKING CRITERIA State the manipulated variable correctly - Time

1

1

State the responding variable correctly - Temperature // Increase in temperature

1

1

State the constant variable correctly - Mass of the water, power of the heater

1

1

θ0 = 25 oC

1

1

Record the readings of θ correctly All five readings of θ correct

1

1

State the value of θ0 within the acceptable range

(i)

(ii)

Tabulate the results for t, θ and Δθ correctly t/s θ / oC Δθ / oC 20 32 7 40 39 14 60 46 21 80 53 28 100 60 35 Give a tick () based on the following: A  Columns t, θ and Δθ B  Correct units for t, θ and Δθ C  All 5 values of θ D  All 5 values of Δθ correct [Note : 3 or 4 values of Δθ correct : ] E  All values of θ and Δθ written as whole numbers or consistent to 0.5 oC. Marks awarded : Number of  6 5 3-4 2 1

Marks 5 4 3 2 1

correct

   



14 5 (d)

5

Draw a complete graph of Δθ against t Give a tick () based on the following: A  Δθ at the y-axis, t at the x-axis B  Correct units at both axes C  Uniform scale at both axes D  5 points plotted correctly [Note : 4 points plotted correctly : ] E  Line of best fit is drawn F  Minimum size of graph 5 x 4 big squares (Big square : 2 cm x 2 cm)

     

(From the origin to the last point) Marks awarded : Number of  7 5-6  3-4  2 1 (e)

Marks 5 4 3 2 1

State the correct relationship between Δθ and t Δθ is directly proportional to t

5

5

1 16

2(a)

(i) State the correct relationship 1 f α // f is inversely proportional to x

1

x

(ii)

Determine the value of 1 x

1 x

1

correctly 1

= 0.5

Draw the intrapolation line from

1 x

= 0.5 to the

given line and from the given line to the f axis

1

State the value of f within the acceptable range 380 Hz  400 Hz

1

(iii) Calculate the gradient of the graph, m, and state the value of m within the acceptable range -Draw a sufficiently large triangle

1

-Correct substitution (Follow candidate’s triangle)

1

-State the value/answer with correct unit 770 Hz m to 790 Hz m // 770 m s-1 to 790 m s-1

1

3

3

15 (b)

State the correct expression

v= (c)

axf D

1

1

Calculate the value of the velocity and state the value within the acceptable range -Correct substitution v=

1.2 × (770) 1.2 × (790) to 2.8 2.8

1

-State the value of velocity with correct unit 330 to 339 m s-1 (d)

1

State two correct precautions - Carry out the experiment in an open space - Position of the eyes must be align with the scale on the metre rule - Place the two speakers closer (so that the value of x is big enough to be measured)

2

1 1 1 Max 2

2 12

SECTION B NO

MARK SUB TOTAL

MARKING CRITERIA

3 (a) (b) (c) (i) (ii)

(iii) (iv)

State a suitable inference The force applied affects the acceleration of an object. State a relevant hypothesis The greater the force, the greater the acceleration Describe a complete and suitable experimental framework State the aim of experiment To investigate the relationship between the force and acceleration of a trolley State the manipulated variable and the responding variable Manipulated variable : Force Responding variable : Acceleration

1

1

1

1

1

1 1

States the constant variable Fixed variable : Mass of the trolley List out the important apparatus and materials Trolley, 5 rubber bands, friction compensated track, 1 ticker timer, ticker tape, a.c. power supply, ruler State a functionable arrangement of the apparatus 1 Rubber band Ticker tape timer Trolley

Ticker tape

Pull Track

16

State the method of controlling the manipulated variable The ticker timer was switched on and the trolley pulled by 1 rubber band stretched to a certain length. (vi) State the method of measuring the responding variable The acceleration of the trolley was calculated from the ticker tape obtained (vii) State how the procedure is repeated to obtain at least 5 sets of results Steps 5 and 6 were repeated with 2, 3, 4 and 5 rubber bands stretched to the same length (viii) Tabulate the data (v)

Force, F /Number of rubber bands 1 2 3 4 5 (ix)

1 1 1

Acceleration, a / cm s–2

State how data will be analysed The graph of acceleration, a against force, F was drawn.

4 (a)

State a suitable inference The current affects the strength of the magnetic field of an electromagnet

(b)

State a relevant hypothesis The greater the current, the stronger the magnetic field

(c)

Describe a complete and suitable experimental framework (i) State the aim of experiment To investigate the relationship between the current and the strength of the magnetic field of an electromagnet. (ii) State the manipulated variable and the responding variable Manipulated variable : current Responding variable : strength of the magnetic field States the constant variable The number of turns of the coil (iii) List out the important apparatus and materials D.c. power supply, ammeter, rheostat, petri dish and retort stand with clamp, paper clips, soft iron rod, insulated copper wire, and connecting wires.

1 1

10 12

1

1

1

1

1

1 1

1

17 (iv) State a functionable arrangement of the apparatus (v) State the method of controlling the manipulated variable The current was switched on. The rheostat was adjusted to obtain a current of 0.5 A (vi) State the method of measuring the responding variable The number of paper clips, N attracted to the soft iron rod was counted (vii) State how the procedure is repeated to obtain at least 5 sets of results The procedure was repeated for the values of current, I = 1.0 A, 1.5 A, 2.0 A and 2.5 A

1

1

1

1

(viii) Tabulate the data 2.5

(ix) State how data will be analysed A graph of N against I is drawn

1 1

10 12

END OF MARK SCHEME