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1

MODUL PENINGKATAN PRESTASI TINGKATAN 5

TAHUN 2015

MAJLIS PENGETUA SEKOLAH MALAYSIA (KEDAH)

MODUL 2

FIZIK

Kertas 2

Peraturan Pemarkahan

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BAHAGIAN A

Soalan Cadangan Jawapan Markah 1(a) longitudinal wave 1 (b) reflection 1 (c) (i) No change 1

(ii) Decreases 1 4

2(a) Latent heat 1 (b) Does work to break the bonds between the molecules //

Weaken the forces of attraction between molecules 1

(c) does not change 1 (d) (i) Q1 is smaller than Q2 1

(ii) Work is done to increase the distance between the molecules 1 5

3(a) (i) direct current 1 (ii) 1

(b) (i) Correct shape 2 complete cycles

1 1

(ii) 4 complete cycles peak value doubled

1 1

6 4(a) Ratio of the potential difference to the current 1 (b) (i) 1.4

1.2

1.17 Ω

1 1

(ii) Increases 1 (iii) filament lamp 1

(c) 1.25 × 1.5 1.875 W

1 1

7 5(a) (i) Decreases 1

(ii) The number of unstable atoms is decreasing // The graph has a negative gradient 1 (b) (i) 20 hours

2 hours 1 1

(ii) Y 1 (iii) The shorter the half-life, the faster the rate of decay. 1

(c) (i) X 1 (ii) Longer half-life / slower rate of decay gives enough time to locate the leakage 1

8 6(a) Degree of hotness of an object 1 (b) (i) The initial temperature of the water in Cup X > cup Y 1

(ii) Cup X : Temperature decreases with time Cup Y : Temperature increases with time

1

(iii) Cup X : Heat is released to the surroundings Cup Y: Heat is absorbed from the surroundings

1

(iv) When the temperature of an object decreases, heat is transfered from the object to the surroundings // When the temperature of an object increases, heat is transfered from the surroundings to the object

1

(c) Thermal equilibrium 1 (d) (i) Shorter time 1

(ii) Cooking oil has a smaller specific heat capacity 1 8

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Soalan Cadangan Jawapan Markah

7(a) The exhaust gases move downwards with a large momentum The rocket gains an equal momentum upwards

1 1

(b) 0 = 152 + 2(-10) h // m × 10 × h =

12 × m × 152

h = 11.25 m

1 1

(c) (i) Aerodynamic // Streamline Reduce air resistance

1 1

(ii) High Larger upward thrust / force // Higher water speed

1 1

(iii) Fins near the tail of the rocket Prevent the rocket from spinning

1 1

10 8(a) Interference 1 (b) Increases 1 (c) (i) Oscillates up and down with a large amplitude 1

(ii) Constructive interference occurs at P 1 (d) Distance increases

Speed of the waves increase Wavelength is longer

1 1 1

(e) (i) In front of the microphone Avoid disturbance // to prevent the sound from speakers being amplified again by the microphones

1 1

(ii) Further distance between the speakers So that positions of constructive and destructive interference are closer together until they are hardly noticeable.

1 1

(iii) S 1 12

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BAHAGIAN B

Soalan Cadangan Jawapan Markah 9(a) Depth // density // acceleration due to gravity 1 (b) (i) Size : P < Q

Depth : P > Q Pressure : P > Q

1 1 1

(ii) The bigger the depth, the smaller the size of the air bubble 1 (iii) The bigger the depth, the higher the pressure on the air bubble 1 (iv) The higher the pressure, the smaller the volume 1

(c) When the volume of a gas is decreased, the same number of molecules move in a smaller space. The molecules collide more frequently with the walls of the bubble. A larger force acts on the walls of the bubble. Therefore pressure increases.

1 1 1

(d) Aspect Suggestion Explanation Attire Water proof //

Tight fitting Does not become wet // Does not absorb water // Less water resistance

Extra equipment Flippers Help the diver to swim under water

Gas tank Light material Smaller size Contains oxygen rich air at high pressure

Smaller weight // Smaller load for the diver to carry Reduces the weight of the tank Diver can stay longer under water

Note : Extra equipment includes mask, pressure gauge, dive watch, dive light, buoyancy control device, signalling device etc

1+1

1+1

1+1

1+1

1+1

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Soalan Cadangan Jawapan Markah 10(a) A substance that has a conductivity between the conductivity of an insulator and

a conductor / metal 1

(b) (i) To increase the conductivity // To reduce the resistivity 1 (ii) Doping with boron produces a p-type semiconductor

Majority charge carriers are holes Doping with phosphorus produces a n-type semiconductor Majority charge carriers are electrons

1 1 1 1

(c) During the first half cycle : the resistance of the diode is low a current flows in the circuit // the diode is forward biased During the next half cycle : the resistance of the diode is very high no current flows in the circuit // the diode is reverse biased

1 1 1 1

(d) thermistor replaces the resistor

resistor replaces the LDR bell replaces the bulb

complete circuit When the surrounding is hot : the resistance of the thermistor decreases the potential difference across the thermistor decreases the potential difference across the resistor increases the base current increases the transistor is switched on the collector current flows

1 1 1 1 1 1 1 1 1 1

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BAHAGIAN C

Soalan Cadangan Jawapan Markah 11(a) (i) Image that cannot be formed on a screen 1

(ii) Object between lens and F

Rays parallel to principal axis passing through F Ray passing through optical centre

Image

1 1 1 1

(b) Aspect Suggestion Explanation Cooling fan Larger diameter Bigger volume of air to cool

the lamp Power of lamp Higher power More light energy to produce

a brighter image Orientation of coloured glass

Inverted To produce an upright image on the screen

Distance between the coloured glass picture and the projector lens

Between f and 2f

To produre a real and magnified image

X is the most suitable - cooling fan with large diameter - high power lamp - inverted coloured glass picture - coloured glass picture at a distance between f and 2f

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1+1 1 1

(c) (i) v = 36

36

1

12

11 +=f

f = 9 cm

1 1 1

(ii) 3612

3

1 1

20

O

F F

I

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Soalan Cadangan Jawapan Markah 12(a) (i) The production of an electromotive force / current in a conductor when it cuts

magnetic flux 1

(ii) The alternating current in the primary coil produces a changing magnetic field The magnetic field cuts the secondary coil The secondary coil has less turns than the primary coil A smaller voltage is induced across the secondary coil

1 1 1 1

(b) (i)

P

S

P

S

N

N

V

V=

3200

80

240S =

V

VS = 6 V The output voltage of the transformer is less than the operating voltage of the bulb

1 1 1

(ii) IP VP = IS VS IP × 240 = 0.75 × 12 IP = 0.0375 A

1 1

(c) Aspect Suitability Explanation Resistivity Low Lower the rate of heat loss Core 8-shape Magnetic field produced by

the primary passes completely through the secondary

Winding of coils Primary and secondary coil over HK

Less leakage of magnetic flux

Lamination of core More thin layers Reduces eddy currents S is the most suitable - low resistivity - 8-shape core - Primary and secondary coil over HK - More thin layers of soft iron lamination

1+1 1+1

1+1

1+1 1 1

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