Sekolah Berasrama Penuh

SEKOLAH BERASRAMA PENUH

PERFECT SCORE PROGRAMME

PHYSICS

SEKOLAH BERASRAMA PENUH 2007

SEKTOR SEKOLAH BERASRAMA PENUH KEMENTERIAN PELAJARAN MALAYSIA

Physics Perfect Score SBP 2007

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SECTION 1 \ Question 1 [ Introduction to Physics ] 1. Diagram 1.2 shows micrometer screw gauge which measures diameter of glass rod. The micrometer screw (ii) gauge has zero error as shown in Diagram 1.1

(a) What is the reading of zero error of micrometer screw gauge? ….……………………………………………………………………………………………………………………………… [1 mark] (b) What is the diameter of the glass rod? ….……………………………………………………………………………………………………………………………….. [1 mark] (c) What is the purpose of measuring of the diameter of the glass rod at several different places ? …………………………………………………………………………………………………………………………………… [1 mark] (d) Why is the micrometer screw gauge more sensitive device compared to the vernier callipers ? …………………………………………………………………………………………………………………………………… . [1 mark] Question 2 [ Forces and Motion ] Diagram 2 shows a skydiver falls freely downwards before the parachute open .

Diagram 2

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i

Name and label the forces which act on the skydiver in Diagram 2.. ……………………………………… ………………………………………………………………………………. [ 2 marks ]

ii.

iii.

Why must the skydiver open up his arms and legs wide when falling freely as shown in Diagram 2.. ..................................................................................................................................................................... . [1 mark ] After a while, the parachute opens and the skydiver keep falling until he reaches a constant velocity. Draw a velocity –time graph to show the motion of the skydiver. [ 2 marks]

Question 3 [ Light ] Diagram 3.1 shows an object O placed in front of a concave lens.

______________________________________________________________________ O 2F F F 2F

DIAGRAM 3.1 (a) (i) Draw ray diagram to show the formation of image in Diagram 3.1. [2 marks] (ii) State two characteristics of the image formed. ……………………………………………………………………………………………………………………….. [1 mark] (b) The concave lens is then replaced with a convex mirror.

______________________________________________________________________ O C F F C

Diagram 3.2

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(i)

Draw ray diagram to show the formation of image in Diagram 3.2. [2 marks]

(ii) State a similar characteristic of the images in Diagrams 3.1 and 3.2. ……………………………………………………………………………………………………………………... [1 mark] Question 4 [Radioactivity] A radioactive source emits a beta particle and a detector is used to detect the juice level in a juice box. The juice box is moved between the detector and a radioactive source in Diagram 4.

Diagram 4 a. What is beta particle? …………………………………………………………………………………..…………………………. [1 mark] b. Name the suitable detector used to detect the beta particle. ………………………………………………………………………………………………………… [1 mark] c. Explain how a radioactive detector can be used to detect whether the drink box is fully filled with juice or not? ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… [2 marks] d. Give one reason for each question below: i Alpha particle source cannot be used to detect the juice level in the juice box. ………………………………………………………………………………………………….………… [1 mark] ii Gamma ray source is not used in this process. …………………………………………………………………………………………………………… [1mark]

Physics Perfect Score SBP 2007

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SECTION 2 Question 5 [ Forces and Motion] Diagram 5 .1 shows a feather and a water droplet falling from the same height. The mass of the feather and water droplet are the same and both are dropped simultaneously at time, t = 0.

Diagram 5.1 The graph in Diagram 5.2 shows the motion of the feather and the water droplet from time t = 0.

DIAGRAM 5.2 a) Name one force acting on the feather and the water droplet. ……………………………………………………………………………………… [ 1 mark ] b) Using Diagram 5.1, compare the surface area of the feather and the water droplet. ……………………………………………………………………………………… [ 1 mark ] Physics Perfect Score SBP 2007

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c) Using the graph in Diagram 5.2, compare the changes in velocity of the feather and the water droplet. ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… [ 3 marks ] d) Using your answer in (b) and (c), state the relationship between the surface area and the final velocity. ………………………………………………………………………………………………………………………… [ 1 mark] Question 6 [ Forces and Pressure ]

Cargo ship A Diagram 6.1

Cargo ship B Diagram 6.2

Diagram 6.1 and Diagram 6.2 show two types of cargo ship sailing on the ocean. Cargo ship B is fully loaded with goods. a) Compare the mass between cargo ship A and cargo ship B. ………………………………………………………………………………………………………………………… [ 1mark ] b) Compare the volume of water displaced by ship A and ship B ………………………………………………………………………………………………………………………… [ 1 mark] c) Relate the mass of ship with its load and the volume of water displaced by the ship. ………………………………………………………………………………………………………………………… [ 1 mark] d) i) Name two forces which act on the cargo ships when they are floating on the water surface. ………………………………………………………………………………………………………………………… [ 1 mark] ii) State the relationship between two forces as mentioned in (d).(i) ………………………………………………………………………………………………………………………… [ 1 mark ]

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e) Name the principle which relate in (b) ………………………………………………………………………………………………………………………… [ 1 mark ] f)

What happens to the cargo ship when it enters the river mouth? Give a reason for your answer. ………………………………………………………………………………………………………………………… …………………………………………………………………………………….................................................. [2 marks ]

Question 7 [ Waves] Diagram 7.1 shows the pattern of the water wave after went through a gap. The experiment was repeated with the difference water wavelengths which went through the same gap, and the resulted pattern is as shown in diagram 7.2.

Diagram 7.1 a. b.

Diagram 7.2

Define wavelength .............................................................................................................................................................. [ 1 mark ] Based on diagram 7.1 and 7.2, state two observations on water wavelengths …………….………………………………………………………………………………………………………

……………………………………………………………………………………………………………………. [ 2 marks ] c. Compare the water wave pattern in diagrams 6.1 and 6.2 which formed after the wave went through gap

d.

................................................................................................................................................................... [ 1 mark] Based on your answers in ( b) and (c), state one relationship between the wavelengths and the wave pattern formed.

..................................................................................................................................................................... [ 1 mark ] e. Name the wave phenomena which occurs in diagrams 6.1 and 6.2 …............................................................................................................................................................... [ 1 mark ]

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Question 8 [ Waves] Diagram 8.1 shows the arrangement of apparatus for Young’s double slit experiment. A white light source is passed through a coloured filter to produce a monochromatic light. Diagram 8.2 shows the pattern of the fringe formed on the screen when a red filter is used. The experiment is repeated by using a blue filter and the fringes formed are shown in diagram 8.3 White light source

Single slit

Coloured filter

White screen Diagram 7.1

Double slit

Red fringe

Diagram 8.2 a.

Blue frige

Diagram 8.3

What is meant by a monochromatic light ? …………………………………………………………………………………………………………..……………… [1 mark]

b.

Using the pattern of fringes in diagrams 8.2 and 8.3, state two observations about the distances between consecutive fringes for the red light and blue light ……………………….…………………………………………………………………………………………………. …………………………………………………………………………………………………………………………. [2 marks]

c.

Compare the wavelengths of red light to blue light ................................................................................................................................................................... [1mark]

d.

Compare the wavelengths of red light and blue light with the distances between consecutive fringes in (b) ……..………………………………………………………………………………………………………………… [1mark]

e

Name the wave phenomenon which forms the pattern of fringes in diagrams 8.2and 8.3 …………………………………………………………………………………………………………………… [1 mark]

Physics Perfect Score SBP 2007

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Question 9 [ Electricity] Diagram 9.1 shows an electric circuit. Voltmeter V1 , V2 and V3 have high resistance. Ammeter A1, A2 and A3 and battery have small internal resistance that can be neglected.. Bulb M1 , M2 and M3 have same resistance.

A1

Switch S1

M1

V3

A2 M2

V1

A3 M3

V2

Switch S2 Diagram 9.1 (a) Based on diagram 9.1, compare the readings of ammeter A1 and ammeter A3 , when the switch S1 is on and switch S2 is off. ..................................................................................................................................................................... . [1 mark] (b) When switch S1 and switch S2 are on , (i)

Compare the brightness of bulb M1 and M2 .

(ii)

...................................................................................................................................................... [1 mark] Compare the readings of voltmeter V1 and voltmeter V2

...................................................................................................................................................... [1 mark] (iii) Write down the equation to relate the readings of voltmeter V1 , V2 and V3 . . …………. ……...................................................................................................................................... [1 mark] (iv) Write down the equation to relate the readings of ammeter A1, A2 and A3

(c) (i)

(i)

. ............................................................................................................................................................ [1 mark] By referring to (a) state the type of circuit connection for the bulb if only bulbs M1 and M3 light up. .................................................................................................................................................... [1 mark] Is the circuit connection above suitable to be used in a domestic wiring system? Give a reason for your answer. ........................................................................................................................................................ .

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[ 2 marks]

SECTION 3 Question 10 [ Electronics] Figure 10.1 shows a circuit with transistor which is used as an amplifier.

X

R1

capacitor

speaker

6V

Y

R2=1000 Ω microphone

Z DIAGRAM 10.1.1 Transistor will function when potential difference between Y and Z is 1V. (a)(i) What is the type of transistor used on Figure 10.1? ……………………………………………………………………………… [1 mark] (ii) What is the function of the capacitor? ……….…………………………………………………………………….. [1 mark] (ii)

What is the maximum value for resistor R1 for the transistor to function? [3 marks]

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(b) Diagram 10..2 shows a logic gate with input A and B, and Diagram 10.3 shows the input signals A X B

DIAGRAM 10.2

1 Input A 0 1 Input B 0 1 Output X 0

DIAGRAM 10.3

(i) Name the type of the logic gate above. …..…………………………………………………………………………………………………………… [1 mark ] (ii) Draw the output signal X for logic gate on Diagram 10.3. [2 mark ]

Physics Perfect Score SBP 2007

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Question 11 [ Forces and Pressure] Diagram 11.1 shows the hydraulic pump which is used to lift a car in a workshop.

Diagram 11.1 (a)

(i)

Name the principle of physics used in the hydraulic pump above.

(ii)

…………………………………………………..…………............................................................. [1 mark] State one important characteristic of oil used in the pump. ………………..…………………………………………………………………………….................. [1 mark]

(b)

The pressure of compressed air at the oil surface is 5000 N m-2 and the cross-sectional area of the piston is 2 m2 . (i)

What is the pressure of the oil in the cylinder?

(ii)

………………………………………………………..…………………………………….................. [1 mark] Calculate the mass of maximum load that can be lifted by the piston.

[3 marks]

(iii)What happened to the position of the piston if the car is replaced with a lorry of bigger mass. ? ……………………………………………………………………………………….. [1 mark]

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(c)

State the necessary modification that can be done to the piston and the cylinder so that a heavier load can be lifted.? …………………………………………………………………………………………….. …………………………………………………………………………………………….. …………………………………………………………………………………………….. [2 marks]

(d)

Name another application for the principle of physics in (a)(i). ………………………………………………………………………………..………….. [1 mark]]

Question 12 [Electronics] (a) Complete the truth table for logic gates P, Q, R and S. (i)

Input

A P

X

B

A 0 0 1 1

B 0 1 0 1

Output X

[1 mark ]

(ii) Input

A Q

X

B

A 0 0 1 1

B 0 1 0 1

Output X

[ 1 mark]

(iii)

Input

A R

X

B

A 0 0 1 1

B 0 1 0 1

Output X

(iv)

[ 1 mark ] Input

A S B

X

A 0 0 1 1

B 0 1 0 1

Output X

[ 1 mark ]

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(b)

Diagram 12.1 shows the combination of two logic gates S.

K S

M

S

L Diagram 12.1 Combination of two logic gates above will produce single logic gate N. (i)

Complete the truth table in table 12.2 for the combination of logic gates in diagram 12.1. K 0 0 1 1

L 0 1 0 1

M

Table 12.2 (ii)

.............................................................................................................................................................. [1 mark] Draw the combination of two logic gates Q to produce a logic gate OR.

(c)

(d)

[ 1 mark ]

Name logic gate N.

[ 1 mark ] Arrange the logic gates P, Q and R inside the box provided in diagram 12.3 so that the output produce is the same as the output in the truth table in 12.4

A B

Q

Input

P R

X

A 0 0 1 1

B 0 1 0 1

Output X 1 0 0 1

Table 12.4 Diagram 12.3 [ 3 marks ]

Physics Perfect Score SBP 2007

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Question 13 [ Light] Diagram 13.1 shows an astronomical telescope in normal adjustment. The power of objective lens is 2 D and the power of eyepiece is 20 D.The diameter of the objective lens is larger than the diameter of eyepiece. Objective lens

Eyepiece

Diagram 13.1 (a) (i) Why is the objective lens with bigger diameter used for the telescope ? ……………………………………………………………………………………... [ 1 mark ] (ii) Calculate the length of the telescope [ 2 marks ] (b) Ali discovered that the astronomical telescope as above, was not suitable to observe the distant object on the earth. He changed the position of the objective lens and eyepiece. He also added two similar optical components , D to obtain a better image. Diagram 13.2 shows a structure of optical device which was modified by Ali. Objective lens

eyepiece

a

Diagram 13.2

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(i)

The telescope in Diagram 13.2 is more appropriate to be used to observe distant objects during a camping activities. Explain. ………………………………………………………………………………..…………………………………….. ………….………………………………………………………………………………………………………….. [ 2 marks ] Name the additional optical component ,D , that can be used to overcome the problem in (b)(i).

(ii)

……..…………………………………………………………………………………………………………….… [ 1 mark ] (ii)

Draw both additional optical components , D , inside the boxes provided in Figure 13.2.

(iii)

[ 2 marks ] Complete the light ray that passes through the objective lens until it gets into the observer’s eyes [ 1 mark ]

(iv)

State the light phenomenon that occurs in the additional optical component.

................................................................................................................................................................... [ 1 mark ] Question 14 [ Forces and Motion] Diagram 14.1 shows the condition of two identical steel springs, before and after a load is placed on them.

DIAGRAM 14.1 (a) (i)

Name the form of energy stored in the spring when it is compressed.

(ii)

…………………………….……………………………………………………………………………………….. [1 mark] Calculate the spring constant.

(iii)

……………………………………………………………………………………………………….…………….. [1 mark] Calculate the energy stored in the spring when it is compressed as in Diagram 14.1 (b).

[2 marks]

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(iv)

Calculate the length of spring, l in Diagram 14.1 (c)

[2 marks] (b)

Figure 14.2 shows the arrangement of springs in the weighing scale.

DIAGRAM 14.2 (i)

State the relationship between compression of the spring and the load.. ………………………………………………………..........................……………………………….. [1 mark]

(iii)

What will happen to the spring when a very heavy load is placed on the weighing scale.? ………………………………………………………….……………………………………………….. [1 mark]

(iv)

Suggest two modifications to the weighing scale so that it can be used to weigh a heavier load. …………………………………………………………….…………………………………………….. ……………………………………………………………………………….………………………….. [2 marks]

Physics Perfect Score SBP 2007

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SECTION 4 1.

Diagram 1 shows a suction pump being used to lift a mirror that measured 1.5 m X 0.5 m X 0.01m . The density of the mirror is 2.5 X 10 3 kg m-3 . The pump obeys atmospheric pressure principle to let the suction pump stick onto surface of mirror.

(a)

Diagram 1 What is meant by atmospheric pressure?

(b)

……………………………………………………………………………………………………………... [1 mark] Explain how the suction pump can lift the mirror with the aid of atmospheric pressure. …………………………………………………………………………………………............................ ………………………………………………………………………………………................................ …………………………………………………………………………………………............................ …………………………………………………………………………………………............................ [ 4 marks]

(c)

The weight of the mirror that can be lifted by the pump depends on pump’s surface area and the difference between the pressure in the semi vacuum space and the surrounding atmospheric pressure. Three suction pumps have different surface area and different atmospheric pressure as shown in table1. suction pump Surface area / m2 Difference in atmospheric pressure / Nm-2 S 0.0025 4.0 x 10 4 M T

0.0040

4.5 x 10 4

0.0035

6.0 x 10 4 TABLE 1

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(i)

Calculate the force produced by the sticker pumps.

(ii)

Calculate the weight of mirror above.

[3 marks]

[2 marks] d)

By using the answer in the c(i) and c(ii) , suggest the most suitable sticker pump to lift the mirror above.Give a reason for your answer. …………………………………………………………………………………………......................... ………………………………………………………………………………………............................ …………………………………………………………………………………………........................ [2 marks]

2.

Diagram 2 shows three beakers P,Q and R , each containing 800 g of water being heated with immersion heater. The power of each immersion heater is 220W. The initial temperature of the water in each beaker is 30 °C and the immersion heaters are switched on for 5 minutes.

Diagram 2 (a)

(b)

State the change of energy when the immersion heater is switched on. ............................................................................................................................. [1 mark] Calculate the energy supplied to the immersion heater when it is switched on. [2 marks]

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(c )

Calculate the energy absorbed by the water in each beaker P,Q and R. (Specific heat capacity of water is 4200 J Kg-1 °C-1)

[3 marks] (d)

(i)

(ii)

Based on (b) and (c), which beaker has the highest efficiency to heat the water? ................................................................................................................................. [1 mark] Give a reason for your answer.

................................................................................................................................... [1 mark] (e) Suggest two steps that can be taken to improve the efficiency of heating the water. …………....................................................................................................................................

(f)

.................................................................................................................................................. [2 marks] After the water in beaker Q reach the maximum temperature 46° C, it was poured into a polysterene container which contain 0.2 kg of water at 28 °C. Calculate the final temperature of the water in the container. [2 marks]

3.

(a) Diagram 3 (a) and Diagram 3 (b) shows the arrangement of apparatus and material for two experiments.

Diagram 3 (a)

Physics Perfect Score SBP 2007

Diagram 3 (b)

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In experiment Diagram 3 (a), when the switch S is on, a deflection in the galvanometer is observed for a while and return back to zero. In experiment Diagram 3 (b), when alternating current is switched on, the steady deflection in the meter is observed. (i)

Name the principle of physics that can explain the deflection of the galvanometer.

(ii)

……………………………………………………………………………………………………… [1 mark] Why are the deflections of the galvanometer in Diagram 3 (a) and Diagram 3 (b) different? ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… [2 marks]

(iii)

For the experiment in Diagram 3 (b), if the bulb lights up normally, calculate the current that flows in the primary coil. [ consider that the transformer is ideal ]

[2 marks] (b) A student wants to build an electromagnet to separate materials that are made of iron from a heap of wasted iron. Table below shows the characteristic of the material provided in the lab. Core Material

Shape of the Material

Type of Metal

A

Soft Iron

B

steel

C

steel

D

Soft iron

Physics Perfect Score SBP 2007

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(i)

Name the most suitable core material to build a simple electromagnet. Give reasons for your answer. …………………………………………………………………………………………………………… ………………………………………………………………………………..………………………… [3 marks]

(ii)

Sketch how the wire is wound around the selected core in (b) (i). Then label the poles of the electromagnet when the current flows through the wire.

[2 marks] (iii)

State two ways how the student can produce a more powerful electromagnet. …………………………………………………………………………………………...................... ............................................................................................................................................... [2 marks]

4.

Diagram 4 shows three transformers X, Y and Z. Each transformer has their own specific number of turns of primary and secondary coils respectively. Each transformer is connected to 240V alternating current supplier. The output for each transformer is connected to electric filament bulbs in different arrangement.

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Diagram 4 (a)

All the transformers are the same and produce the same output voltage. Calculate output voltage for the transformers.

[2 marks] (b)

When the switch is on, 0.25 A current flows through the primary coil in each transformer. All the bulb lights up normally. (i)

Calculate the input power for each transformer.

(ii)

Determine the output power for each transformer.

[2 marks]

[3 marks ] (iii)

Between X, Y and Z transformer, which one has the highest efficiency? ................................................................................................................................. [1 mark]

(iv)

Give a reason for your answer in (b) (iii) ................................................................................................................................. ................................................................................................................................. [1 mark]

(c)

(i)

If l the transformers are ideal, what is the output power ?

[1 mark]

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(ii)

State one reason why the efficiency of the transformer is less than 100%.

(iii)

...................................................................................................................................................... [1 mark] State one step to overcome the problem in (c) (ii) above. ……………………………………………………………………………………….…………………….. [1 mark]

(a)

Diagram 5.1 shows a graph of the number of neutron and proton in the stable nucleus.

Number of nutron

5.

Number of proton

DIAGRAM 5.1 Phosporus-32 atom has 17 neutron. (i) Calculate the number of proton in the nucleus phosporus-32? .............................................................................................................................................. [1 mark] (ii) On the graph in Diagram 5.1 , mark ‘X’ to show the position of phosporus-32. [1 mark] (iii) According to graph in Diagram 5.1 , explain why phosporus-32 is radioactive? ...........................................................................................................

(b)

............................. [1 mark] P and Q are 2 elements whose half life is 12 hours and 2.6 years respectively. Both elements undergo radioactive decay and emitted  ray to become stable . (i)

State the change to proton number and nucleon number of element P after emittting  ray. ................................................................................................................................. ................................................................................................................................. [2 marks]

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(ii)

State the change to the activity of element P and Q after 24 hours. ................................................................................................................................. ................................................................................................................................. [2 marks]

(iii) State the change in mass from the original mass after 12 hours. ................................................................................................................................. [1 mark] (c)

A factory produces aluminium plate 1 mm thick. The thickness of aluminium plate can be detected by a detector which is connected to radioactive counter equipment as shown in Diagram 5.2. Radioactive source emitting  ray is used.

Diagram 5.2 (i) Explain why radioactive source that emitted  ray and  ray are not suitable? ........................................................................................................................................................ ........................................................................................................................................................ [2 marks] (ii) Between element P and element Q, which the more suitable element to be used as radioactive source in radioactive counter above. Give a reason for your answer. ......................................................................................................................................................... ......................................................................................................................................................... [2 marks]

Physics Perfect Score SBP 2007

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SECTION 5 6.

Ballast tank Diagram 6 Diagram 6 shows the internal structure of a submarine and the position of ballast tanks. Explain how a submarine that floats on the sea surface can sink underwater. ………………………………………………………………………………………………………………….…… …………….………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………. [3 marks] 7.

Diagram 7 shows a seaside during the day.

Land

Sea Diagram 7

Using the specific heat capacity concept, explain why sea breeze occurs during day time. ………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………… ………………………………………………………………………………………………….....................

[ 4 marks]

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8.

Diagram8 shows the model of an electricity transmission system. Transmission wire at 24 V a.c

Power station

Industry at 8 Va.c House at 6 V a.c

Diagram 8 Most of the electric energy that we are using come from hydroelectric and thermal power station. This power station is connected to each other using cable to transmit electric energy to industries, office, school and house. This system called National grid network. State the form of energy transfer at hydroelectric power station. Explain the importance of National grid network system in electricity transmission to consumers. …………………………………………………………………………………………………………… ……………………………………………………………………………………………………………. ……………………………………………………………………………………………………………. [ 5 marks]

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9.

Diagram 9 shows a wire in magnetic field. The wire moved upwards when current flows through it. Upwards

Diagram 9 Explain why the wire moved upwards. ............................................................................................................................................................. ............................................................................................................................................................. ............................................................................................................................................................. ............................................................................................................................................................. [4 marks] 10. Diagram 10 shows a Cathode-Ray Oscilloscope.

Diagram 10 Explain how the Cathode-Ray Oscilloscope can be used to measure the potential difference of a dry cell. ………………………………………………………………………………………………………………..……... ………………………………………………………………………………………………………………………... ………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………….... [ 4 marks ]

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SECTION 6 : CONCEPTUALISING SKILL Question 1 Forces and Motion Diagrams 1.1 and 1.2 show a load is being lift up.

Ground Diagram 1.1

Ground Diagram 1.2

(i)

What is potential energy. State its unit.

(ii)

Based on diagrams 1.1 and 1.2 , compare the load’s position while being lift up. State the relationship between the load’s position with work done in lifting the load

[2 marks]

[4 marks] Question 2 Light Diagram 2.1 and 2.2 shows the virtual image fomed by a plane mirror and convex mirror.

Diagram 2.1 Image formed by plane mirror.

(i)

Diagram 2.2 Image formed by convex mirror

What is meant by virtual iamge ? [ 1 mark]

(ii)

Observe diagram 2.1 and 2.2 and compare the characteristics of both images. Hence describe how the images are formed and state the relevant physics concept. [ 5 marks ]

Physics Perfect Score SBP 2007

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Question 3 Electromagnetism Diagram 3.1 and Diagram 3.2 show wire coils connected to the ammeters, switches and d.c. power supply.

Diagram 3.1

Diagram 3.2

When the switch is on and iron filings of the same amount is spread on each of the cardboard surface, the pattern of the iron filings is formed as shown in the diagrams. (a) What is meant by magnetic field? [1 mark] (b) Using Diagram 3.1 and Diagram 3.2 , compare the number of turn of the coils, the pattern of the iron filings and the angle of deflection of the ammeter indicator. [3 marks] (c) State the relationship between the strength of the magnetic field and (i) the pattern of iron filings, (ii) the number of turn of the coils. [2 marks] Question 4 ELECTRONICS Diagram 4.1 and 4.2 show a bulb is connected to a diode and a dry cell.

Diagram 4.1 (i)

Diagram 4.2

Observe Diagram 4.1 and 4.2 .Compare the brightness between two bulbs .Relate the brightness of the bulbs in diagram 4.1 and diagram 4. 2 to deduce the relationship between dry cell poles connection and current flows through the diode . [ 6 marks]

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Question 5

RADIOACTIVITY

The production of nuclear energy and volume detection are the two examples of application of radioactive substances in industry . Table 5.1 shows reaction equation and total mass of atom between before and after nuclear fission process. Nuclear Fission After Reaction

Before Reaction

239 Persamaan

Total mass of atom

1

Pu +

141

n

94

97

Ba +

0

Sr + 2

56

240.06082 a.m.u

1

38

n

+ energy

0

239.85830 a.m.u TABLE 5.1

Table 5.2 shows reaction equation and total mass of atom before and after nuclear fusion process Nuclear Fusion After reaction

Before reaction 2

Equation

Total mass of atom

4

3

H

+

1

H 1

5.03013 a.m.u

1

He 2

+

n

+

energy

0

5.01043 a.m.u TABLE 5.2

a. i. What is meant by nuclear fission ? [1 mark ] ii. Using the information in table 5.1 and 5.2 only, compare the nuclear fission and nuclear fusion and then relate the relationship between mass and energy released [ 5 marks ]

Physics Perfect Score SBP 2007

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SECTION 7 : PROBLEM SOLVING ( QUANTITATIVE) Question 6: Forces and Motion Diagram shows a car travelling at 20 ms-1 on a level road. At this speed the car has to overcome a total force of 500 N opposing the car.

(i) Calculate the distance travelled by the car in 5 seconds. [2 marks] (ii) State the value of the driving force produced by the engine to maintain a uniform speed. [ 1 mark] (iii) While on the level road and travelling at 20 ms-1 , the driving force suddenly becomes zero. The mass of the car is 800 kg . Calculate the deceleration of the car [2 marks] Question 7 Forces and Motion

F (N)

Graph F against x of spring P and spring Q

8

P

7 6 Q

5 4 3 2 1 0

0.1 0.2

0.3

0.4

0.5

x (cm)

The graph shows the relationship between the stretching force, F and the spring extension, x. (a) Calculate the spring constant of P and Q. [3 marks] (b) Using the graph, calculate the elastic potential energy stored in spring P when its extension is 0.5 cm . [2marks]

Physics Perfect Score SBP 2007

32

Question 8 : Heat

A copper block with mass of 200 g is placed in boiled water. After the thermal equilibrium achieved, the block is taken out and put it back in 100 cm 3 water at 28˚ C. [ specific heat capacity of copper = 379 J kg -1 C-1 , specific heat capacity of water = 4200 J kg -1 C-1 , water density = 1 g cm -3 ] i) What is the initial temperature of copper block before we put it in 100 cm 3 water at 28˚ C? [1 mark] ii) What is the mass of the 100 cm 3 of water? [2 marks] iii) What is the final temperature of the water? [2 marks] Question 9

The mass of the load is 0.8 kg and is lifted to a height 1.5 m in 4.0 second. The reading of the ammeter and voltmeter are 1.2 A and 5.0 V respectively. Calculate (i) useful energy output of the motor (ii) Energy input to the motor? (iii) the efficiency of the motor. [6 marks]

Physics Perfect Score SBP 2007

33

Question 10 Electronics Diagram 10 shows a fire alarm circuit using a transistor as a switching divice.

Bell

DIAGRAM 10 Resistor T is a thermistor. G will switch on and ring the bell if the potential difference Y and Z exceed 3.2 V. S is a fixed resistor with resistance of 6 kΩ. When there is a fire burning, resistance at T is 3.5 kΩ. . Calculate the potential difference : (i) across T [2 marks] (ii) across S [2 marks] (iii) Is the bell ringing at that time? Explain your answer. [2 mark]

Physics Perfect Score SBP 2007

34

SECTION 8 : PROBLEM SOLVING ( QUALITATIVE) 1. [Heat]

DIAGRAM 1 Diagram 1 shows a model of an incubator used to hatch eggs. The temperature in the incubator must be maintained around 39oC. Every part of the eggs must receive uniform heat. The eggs are hatched in about 20 days. Using an appropriate concept in physics, explain the modification required to the above incubator so as to efficiently hatch about 200 eggs. [10 marks] 2. [Forces and Pressure]] Diagrams 2.1 and 2.2 illustrate the working principle of a hydrometer. The depth to which the test tube sinks depends on its surrounding liquid.

Water Air

Alcohol Alkohol Sand

DAIGRAM 2.1

DIAGRAM 2.2

Explain how you would design a hydrometer that can determine a wide range of densities of liquid, using the idea of the working principle of a hydrometer shown above. Draw a diagram that shows the design of your hydrometer and in your explanation, emphasise the following aspects : (i) (ii) (iii) (iv)

The stability of the hydrometer, The sensitivity of the hydrometer, The ability to measure a wide range of densities of liquids, The calibration of the hydrometer. [10 marks]

Physics Perfect Score SBP 2007

35

3 [Waves] Diagram 3, shows the seashore of a fishing village. During the rainy season, waves are big. One year the waves eroded the seashore, caused the jetty to collapse and damaged the fishermen’s boats

Bay

DIAGRAM 3 To prevent similar damage in the future, the fishermen suggest building retaining walls and relocating the jetty. Make further suggestions of ways to help the fishermen solve their problems. You should use your knowledge of reflection, refraction and diffraction of waves to explain these suggestion, to include the following aspects : i. ii. iii.

the design and structure of the retaining wall the location of the new jetty. the size or energy of the waves. [10 marks ]

.

Physics Perfect Score SBP 2007

36

4. [ Electromagnetism]

Diagram shows the electromagnetic Lifting Machine using the principle of eletromagnetic. Using suitable physics concept, explain the modification that must be made to increase the lifting ability of the machine. [10 marks] 5 [Electronics] Transistors is an important device in electronics. Transistors can be use as a current controller or automatic switching. Diagram 5 shows a circuit with a transistor as a current controller.

DIAGRAM 5

An engineer want to invent an automatic switching circuit to control an air conditioner. This air conditioner will swith on during hot wheater and switch off during cold wheater. Explain how you can built the circuit using your knowledge about transistors; (i) Explain the operation of the circuit and how the circuit work during the hot weather (ii) Explain how the circuit work during cold weather (iii) Draw the circuit diagram . [10 marks ]

Physics Perfect Score SBP 2007

37

SECTION 9 : DECISION MAKING SKILL

6 [Forces and Pressure] A automotive student ordered to investigate charecteristics of liquid for using in brake hydraulic system of car. Diagram 6 shows an arrangement of hydraulic.

DIAGRAM 6 Table 6 shows characteristic for four type liquid that using as brake liquid above. Liquid characteristic

Boiling point / ºC

Specific heat capacity /J kg-1 ºC-1

Density / kg m-3

A

357

140

13600

B

130

2500

800

C

100

4200

1000

D

55

2200

790

Rate of vaporation Low Low Average High

TABLE 6 Based on Table 6 above, describe the characteristics of liquid appropriation so that the liquid used as liquid in the apparatus above. Next select which liquid more appropriate used for this purpose. Give your reason. [10marks]

Physics Perfect Score SBP 2007

38

7. You are asked to investigate the features of heating material and the design of a pressure cooker as in Table 7. Safety valve

The features of pressure cooker :  Specific heat capacity of the body of pot : 1400

Jkg 1 o C 1  Specific heat capacity of the handle of pot : 890

P

Jkg 1 o C 1  Thickness of the pot : 5.0 mm  Has safety valve The features of pressure cooker : Safety valve

 Specific heat capacity of the pot : 385 Jkg 1 o C 1  Specific heat capacity of the handle: 890 Jkg 1 o C 1  Thickness of the pot : 3.0 mm  Has safety valve

Q

The features of pressure cooker :  Specific heat capacity of the pot : 449 Jkg 1 o C 1  Specific heat capacity of the handle of pot : 385

R

Jkg 1 o C 1  Thickness of the pot : 1.0 mm

safety valve S

The features of pressure cooker :  Specific heat capacity of the pot : 502 Jkg 1 o C 1  Specific heat capacity of the handle of pot : 2300

Jkg 1 o C 1  Thickness of the pot : 5.0 mm  Has safety valve The features of pressure cooker :  Specific heat capacity of the body of pot : 1400

Jkg 1 o C 1

T

 Specific heat capacity of the handle of pot : 890

Jkg 1 o C 1  Thickness of the pot : 5.0 mm Explain the suitability of each features described in Table 7 and then determine the most suitable pressure cooker to be used. Give a reason for your choice. [10 marks]

Physics Perfect Score SBP 2007

39

8.

Diagram 8 shows circuits P, Q, R and S that are used to determine the resistance of a constantan wire.

DIAGRAM 8 You are asked to determine the resistance of a constantan wire. Study the circuits, P, Q, R and S in Diagram 8 and consider the following aspects: - the usefulness of the measuring instruments. - the usefulness of certain components in the circuit. - the way the measuring instruments and other components are connected in the circuit. Explain the suitability of the above aspects and hence, choose the most suitable circuit to determine the resistance of the eureka wire. Justify your choice. [10 marks] 9.

The sound of a music note from a guitar depends on the strings of the guitar. Each string has its own natural frequency. String

Diameter

Tension

Strength

String material

P

Small

low

medium

jute

Q

Small

High

high

steel

R

Medium

Medium

low

plastic

S

Large

low

medium

jute

TABLE 9 Table 9 shows the characteristic of strings P, Q, R and S. Explain the suitability of the characteristics of strings to be used in a guitar that can produce high pitch sound and will not break easily when it is strummed. Determine the most suitable string to be used and justify your choice. [10 marks]

Physics Perfect Score SBP 2007

40

10. Diagram 10 below shows a boiler that using to boil water at home.

DIAGRAM 10 Table 10 below shows characteristics of material that can be used to make immerson heater . Characteristic

Density/ (kgm-3)

Freezing point / 0C

Resistivity/ Ωm

Rate of corrosion

Matertial P Q R S T

3500 5000 2500 7000 7900

5500 6550 7500 8050 9000

2.0 x 10-7 4.0 x 10-7 3.0 x 10-7 7.0 x 10-7 8.0 x 10-7

Average Low Low Average Low

TABLE 10 You are asked to investigate the characteristics of the materials above. Explain the suitability of each characteristic in table 10 and then determine the most suitable material to make immersion heater. [10 marks]

Physics Perfect Score SBP 2007

41

MODEL ANSWER PHYSICS PERFECT SCORE 2007 SECTION 1 1.

(a) (b) (c) (d)

-0.03 mm 3.83 mm – (-0.03 mm) = 3.86 mm increase accuracy / to get more accurate reading can detect a small change of reading [4 marks]

2.

i. ii. iii.

weight and upthrust Increases the surface area / Increases the air resistance v-t graph

[2marks] [1 mark] [2 marks]

v

t 3

O a.

i. correct ray diagram ii. virtual, upright and magnified

C

b.

I

F

i. correct ray diagram ii virtual ,upright and diminished

[2 marks] [2marks]

I

C

[2 marks] [2 marks]

1

4. a. Beta particle is fast moving electron. b. Geiger Muller Tube c. The reading of the detector is high when the drinkbox not full. The reading will be low (minimun limit) when the level of juice on the real level. d. i. Penetrating power of alpha emission is weak than other. So it can’t penetrate the paper box (drinkbox) and can’t detect the full level of drinkbox ii. The gamma ray has most penetrating power and high frequency and high energy. So it is very dangerous to our health. 5.

6.

(a) (b) (c) (d)

(a) (b) (c) (d) (e)

8

[1 mark] [1 mark]

(a) Gravitational force / (buoyancy forces / up thrust / frictions / air resistant / drags/ weight [1 mark] (b) (Surface area) feather > (Surface area) water droplet /more surface area for feather // other wise [1 mark] (c) Similarities: Decreasing in velocity/ deceleration / initial acceleration constant / increasing in velocity : Final velocity /terminal velocity / final velocity constant / final acceleration zero / no change in velocity at the end. Different: Velocity (terminal) water droplet > velocity (terminal) feather [2 marks ] (d) Velocity (terminal) increase when the decrease of surface area / Velocity (terminal) inversely proportional with the surface area. [1 mark]

(e) (e)

7

[1 mark] [1 mark] [1 mark] [1 mark]

The mass of the B cargo is larger The volume of water displaced by ship B is bigger than ship A The bigger the mass of the load, the bigger the volume of water displaced (i) The buoyant force, the gravitational force (weight) (ii) F=W The Archimedes Principle / buoyancies principle (i) sink deeper (ii) The density of the river water less than the sea water. Length between the two crest / trough / consicutive wave front The water wavelength remains constant after went through the gap. The wavelength in 6.3 is greater than 6.2

[1 mark] [1 mark] [1 mark] [1 mark] [1 mark] [1 mark] [1 mark]

[1 mark] [2 marks]

Curvature of the wave pattern in fig. 6.3 is more greater / Diffraction of waves is more in 6.3 [1 mark] The greater the wavelength, the wave pattern more spread or curve after went through gap. [1 mark] Diffraction [1 mark]

(a) (b)

Light has one wavelength only / Frequency or light have one colour/ one basic colour. [1 mark] Similarity : The distance between consecutive blue/red fringes are equal. Differences : The distance of consecutive red fringe > The distance of consecutive blue fringe [2 marks] (c) Red wavelength >blue /  red>  blue / red > blue [1 mark] (d) The greater the wavelength the greater the distance of consecutive fringe// The wavelength is directly proportional to the distance /   x / [1 mark] (e) Interference / Diffraction [1 mark]

2

9

(a)

same [1 mark]

(b)

(i) M1 brighter than ebih cerah [1 mark] (ii) V1 is bigger than V2 [1 mark] (iii) V3 = V1 +V2 (iv)A1 = A2 + A3 [1 mark]

(c)

(i) Series circuit [1 mark] (ii)Not suitable If one bulb blown up ( does not light up) all the bulb will not funtion

[2 marks]

SECTION 3 10.

(a)

(i)

npn [1 mark]

(ii)

to avoid direct current from battery flow through the microphone [1 mark]

(iii)

Vzy = 1 V VXY = 5 V R1 x 6 = 5 R1 + 1000 R1 = 5000 Ω [3 marks]

(b) (i)

NAND [1 mark]

(ii) [2 marks]

11

(a) (i) Pascal Principle (ii) Oil cannot be compressed (b) (i) 5 000 Nm (ii) F=PA = 10 000N m = 1 000 kg (iii) move downward ( c) Increase diameter of the piston Use thicker wall cylinder (d) Hydraulic brake

[1 mark] [1 mark] [1 mark] [1 mark] [3 marks] [1 mark] [2 marks] [1 mark]

3

12.

(a) (i) 0111 (ii) 1000 (iii) 0001 (iv) 1110 (b) (i) 0001 (ii) DAN

[1 mark] [1 mark] [1 mark] [1 mark] [1 mark] [1 mark]

(c)

Q

[1 mark]

Q

(d) [3 marks]

Q P R

13 (a) (i)To focus more light ,so that image are brighter (ii) f 0=

[1 mark]

½ m / 0.5 m / 50 cm or

f 0=

1/20 m / 0.05 m / 5 cm

Length = ( 50 + 5 ) = 55 cm (b) (i) Telescope is long / not convenience to carry around Produce inverted image [2 marks] (ii) Prism 45˚ (iii) + (iv)

(iii)Correct arrangement of first prism Correct arrangement of second prism [ Note: Accept 2-D or 3D diagram of prism ] Correct ray diagram (v) Total internal reflection

[2 marks]

[1 mark]

[2 marks] [1 mark] [1 mark]

4

14. (a) (i) Elastic potential energy

[1 mark]

F 3.6 , k x 4 -1 k = 0.9 N cm

(ii) k 

[2 marks]

(iii) E = ½ Fx = ½ x 3.6 x 4/100 = 0.072 J 5 (iv) x  0 .9 l = 12 – 5.56 = 6.44 cm

[2 marks]

[2 marks]

(b) (i) The compession of the spring is directly proportional to the load [1 marks] (ii) Exceed the elastic limit of the spring/ Spring does not return to its original condition after the applied force has been removed. [1 mark] (iii) Connect the spring in parallel Use spring with larger spring constant. Use spring with smaller diameter. [2 marks]

SECTION 4 1. (a) (b)

( c)

Atmospheric pressure is the weight of air acts on a surface. It caused by air molecule collision on the surface.. [1mark] Air pressure in the sticker decrease. Have the different between pressure in the pump and the air pressure surrounding. The force is produce Force > mirror weight [4 marks] (i)

( Use F = PA ) Force is produced by pump S = 4.0 x 104 x 0.0025 = 100 N Force is produced by pump M = 4.5 x 104 x 0.0040 = 180 N Force is produced by pump T = 6.0 x 104 x 0.0035 = 210 N

(ii)

mirror weight

[3 marks] = ρVg = 2.5 x 10 3 x 1.5 x 0.5 x 0.01 x10 = 187.5 N [2 marks] (iii)

Pump T is choosed because force is produced bigger than mirror weight. [2 marks]

2.

(a) (b)

Electrical energy to heat energy E = pt = 220 x (5x 60) // 220 x 5 = 6.5 x 104 J

[1 mark ] [2 marks]

5

(c )

Beaker P, Heat = mcӨ = 0.8 x 4200 (38 – 30) = 26880 J Beaker Q, Heat = 0.8 x 4200 x (46 – 30) = 53760 J Beaker R , Heat = 0.8 x 4200 x (40 – 30) = 33600 J

(d)

(i) (ii)

(e)

Immerse the immersion heater fully in the water // wrap the beaker// // cover th beaker // use beaker of higher specific heat capacity

(f)

3

Beaker Q [ 1 mark] The increase of water temperature is higher with the same energy supplied [1 mark]

0.8x 4200 x (46-T) = 0.2 x 4200 x (T-28) T = 42.4 °C

(a)

(i) (ii)

(iii)

[3 marks]

[2 marks]

[ 2 marks[

Electromagnetic induction [1 mark] At (a) flux changes in a while (when switch is on) // the coil cuts the magnetic field in a while // The coil experience flux increases. At (b) flux changes continously / always happened // solenoid always cuts the magnetic feild [2 marks] VpIp = 36 Ip =

36 240

= 0.15 A [2 marks] (b)

(i)

D U shape can produce surface / lower part that consist of two polars: ’North and South’. Electromagnetic strength is higher. Iron core is easy to magnetised and demagnetised. [3 marks]

(ii)

U shape core is wound with the number of turns of wire and the direction of current flow to produce both poles North and South at the end. North and South pole are labelled correctly follow the turns and direction of the current flow without consider the shape. [2 marks]

.

6

(iii) 4.

(a)

(b)

Increasing the number of turns. Increase the magnitude of current flow inside the solenoid. 1200 V = 240  800 = 160V (i)

[2 marks]

[2 mark]

P = 0.25 x 240 = 60 W

[2 marks]

(iii)

X Transformer = 36 W Y Transformer = 48 W Z Transformer = 54 W Z transformer

[3 marks] [1 mark]

(iv)

Highest in Output power / Lowest in power lost

(ii)

Kuasa output Kuasa input

 100% Highest [1 mark]

(c)

(i)

60 W

(ii)

Resistance of coil wire / Heat produced / Flux leaking / Eddy current produced / Lost of energy in term of magnetised and demagnetised [1 mark] Use the low resistance wire / design the efficient core shape / Use laminated iron core/ Use soft iron core [1 mark]

(iii)

5.

(a)

(i)

[1 mark]

number of proton = 32 – 17 = 15

[1 mark]

(ii)

[1 markah] (iii)

Phosphorus -32 situated outside the graph that shown the stabile atomic nucleus. [1 mark]

7

(b)

(i)

The atomic nomber element P incease 1.

[1 mark]

Nucleon no. Does’t change

[1 mark]

Element P activity change ¼ from origin activity.

[1 mark]

The activity of Element Q activity does’t change

[1 mark]

(iii)

The mass of element P decrease to half from original mass.

[1mark ]

(i)

Penetration power  ray is weak and can’t penetrate aluminium plate. [1mark ] Penetration power  ray is too high and effect our health. [1 mark ] P element [1 mark ]

(ii)

(c)

(ii)

Half life not too long.

[1 mark]

SECTION 5 6.   

The submarine has a ballast tank in front and at the end of submarine. A water is filled in the ballast tank to increase the density of the submarine // the weight of submarine. The submarine will sank in the sea when it weight is bigger than buoyant force. [3 marks]

7.     8.

The specific heat capacity land less than sea water. During the day time, the land is warmer than the sea. Air above the land is hot and less dense, so it will move up. The cooler air from sea more dense move to land.

Potential energy      

kinetic energy/ mecanical energy

1 1 1 1 electric energy

Electric supply is continuously Electric supply is depends on region, the region like city needs more electric supply than interior region. Peak hour need more electric supply. If one region is black out, the source of electric supply can be taken from another region. Reduce the cost. Easy to manage and to repair.

* Choose any FOUR from the list. 9.   

A magnetic field is produced when current flow through a wire. This cause the interaction between a current-carrying conductor and the magnetic field. A catapult field is produced and cause the wire to move.

1 1 1 1

Connect the dry cell terminal to the Y-input of CRO. The Y-gain is set to a value so that the direct current wave form displayed on the screen CRO. Determine the distance / part of y-axis. Potential different = ( Y-gain scale) x (Vertical distance of direct current wave)

1

10.    

1 1 1

8

SECTION 6 . Question 1 (i)

1.The energy an object has because of its position. 2.Unit Joule/ Nm

(ii)

1. The load in diagram 1.1 is higher than in figure 1.2. 2. The load has weight. 3. The work done = gravitational potential energy / mgh. 4. The higher the position of the load , the higher the work done.

Question 2. (i) A virtual image is an image that cannot be formed on a screen (ii) 1. Both images are upright 2. Image of the convex mirror is smaller 3. Light from an object is reflected by the mirror 4. angle of incidence = angle of reflection 5. Physics concept – Reflection of light. Question 3. (a) magnetic field region (b) 1. The number of turns of the coil in diagram 3.2 is more // vice versa 2. The arrangement pattern of the iron filings in diagram 3.1 is further apart. 3. The angle of deflection of diagram 3.2 is more. (c ) 1. The closer the pattern of iron filing the greater the strength of magnetic field. 2. The strength of magnetic field increases as the number of turns increases// vice bersa. Question 4 1 2.

3. 4. 5. 6.

The light bulb in diagram 4.2 does not light up while the light bulb in diagram 4.1 light up In diagram 4.2 the negative terminal cell is connected to the anode. This increase the junction resistance in diagram 4.2 The current cannot flow through the junction. The diode in diagram 4.2 is reversed bias. Concept – Diode allows current to flwow in one direction.

Question 5. (i) Nuclear fission is the splitting of a heavy nucleus into two lighter nuclei,which subsequently emit either two or three neutrons and release of large amounts of energy. // the high number mass/ high nucleon number to small nucleus. (ii).

Difference: State that nuclear fission involves the fission of heavy nucleus. State that nuclear fusion involves the combination of lighter nuclei Similarities: State that decrease/loss of mass after the process occurs. State that the neutrons are produced. State that nucleon number/ mass number/ atomic number before and after are the same E = mc2 // loss of mass/ mass defect directly proportional to the energy released .

9

SECTION 7 Question 6. (i)

Distance = 20 x 5 = 100 m

(ii) (iii)

500 N a = F / m = -500 800 = -25 ms-2

Question 7 (a) 1. The spring constant = gradient of the graph 2. For P , spring constant = 8 / 0.5 = 16 N cm-1 3.For Q , spring constant = 3 / 0.5 = 6 Ncm-1 (b)

Elastic potential energy = ½ x 8 x 0.5 x 10 -2 =0.02 J Question 8 (i) 100°C (ii) m=ρV = (1) (100) = 100g (iii) .2 x 379 ( 100-T) = 0.1 x 4200 x (T-28) T = 39° C Question 9 (i) Useful energy output =0 .8 x 10 x1.5 =12 Joule (ii) Energy input = Pt = 1.2 x 5 x 4 = 24 J (iii)

Efficiency = 12/24 x 100 % = 50 %

Question 10 (i) Potential difference across P = 3500 x 6 = 2.2 V (3500 + 6000) (ii) Potential difference across Q, 6000 x 6 = 3.8 V (3500 + 6000) (iii) Ring because the voltage across Q exceed / greater than 3.2 V. SECTION 8 1. CHARACTERISTIC EXPLANATION Add number of bulb / arrange the To ensure all the eggs get uniform heat eggs in eggs container / used fan Used insulator or wrap the eggs To control / harmonize / to maintain the temperature or prevent heat loss to the surrounding Used shiny material / silver colour / As a heat reflector white / mirror Used water proof material / strong / Eggs not wet or break stiff / sponge Thermostat To control / harmonize / to maintain the temperature 10 marks

10

2.

Scale

Lead shot Bulb CHARACTERISTIC hydrometer diagram placed lead shot / steel ball into glass bulb. used smaller diameter of the tube / long stem used the bigger bulb.

EXPLANATION to keep the hydrometer upright. to increase the scale range of measurement to increase the buoyant force or to increase the volume of liquid displaced

Calibration : put hydrometer into the low density liquid (parafin/alcohol) marked the liquid level on the hydrometer hydrometer is then put into high density liquid (water) marked the liquid level. divided the space between two marked equally. Any 10 marks

3.

Suggestions Design a inclined concrete barrier Design a curve barrier Jetty is build at bay Built diffraction barrier (aperture/slit very small) for ship passage Barrier is built from a strong material/concrete Design the higher barrier

Explanations wave is refracted with velocity/ magnitude /decreasing wavelength Can be absorb waves/decreasing reflection Water at the bay is stiller To diffract the wave / diffracted Not easily corrosive/broken// can prevent a strong /hard wave water cannot over flow 10 marks

11

4. Characteristics The number of turn in the solenoid. A U-shaped iron core is used

Increasing the number of turn in the solenoid increases Increasing the current magnitude The type of core should be laminated soft iron. Increasing of the thickness of the wire.

Explanations Attaching a steel plate to the ends of a U-shaped iron core 1 field lines in an “ forms a closed iron loop. The magnetic iron circuit” increases the strength of0 the electromagnet. m a r k s Increasing the number of turn so Increases the magnetic field and effects of the windings of the solenoid. Increasing the current will increase the strength of the magnet Soft iron is used because it is easily magnetized and increasing the magnetic field in the coil The greater the thickness of the wire, the greater the strength of the magnetic field of the electromagnet.

5. (a) (i) – During hot weather, resistance at termistor decrease ,potential difference across - Potential difference across R will increase - This will produce bigger base –current , and will increase the collector current - Finally, electric relay will switch on the air conditioner. (ii) -

(iii)

4 marks During cold weather , resistance at termistor increase. Potential difference across thermistor will increase. Potential difference across R will decrease. This will produce smaller base-current and no current flow in collector circuit. Finally, electric relay will swith off the air conditioner. 4 marks Circuit diagram

Thermistor

2 marks

SECTION 9

6. Characteristics

Explanation

Reason

Safety valve

needed

Thickness of the pot Specific heat capacity of the pot Specific heat capacity of

High Low

To release extra steam so that the pressure in the cooker does not reach a dangerous stage To withstand high pressure Heats up quickly and food will be cooked faster Heats up slowly and can be held with bare

High

12

the handle S is chosen

hands Reasons: It has safety valve, high thickness, low specific heat capacity of the pot, high specific heat capacity of the handle.

Characteristics

Explanation

Reason

Boiling point

High

So that liquid slow to heat

Specific heat capacity

High

So that it can’t be easily hot

Density

Average

High density, liquid more heavy

Rate of vaporation

Low

7.

Liquid B is chosen

Liquid volume will be decrease faster if rate of vaporation high Reasons: Boiling point high, specific heat capacity average, rate of vaporation low

8. Characteristics

Explanation

Reason

Size and height hydrometer stem Bulb diameter

Stem thin and long

To increase accuracy

Big

Bouyant force high// Displace more liquid

Bulb A

Bulb contains lead shot Glass wall

Hydrometer upright/ lowing gravity centre/ more stable No erode by acid

Hydrometer wall Hydrometer K is chosen

Reasons: stem thin and long, diameter air bulb big, bulb contained lead shot and stem glass walled

9. Characteristic

Suitable property

Reason

Diameter

small

High frequency hence high pitch

Tension

high

High frequency hence high pitch

Strength

high

Does not break easily

String material

Steel

Lasting and does not break easily

Q is chosen

Reason: Small diameter, high tension, high strength and its made of steel.

10.

13

Characteristics

Explanation

Reason

Density

Low

So that the loop will be light

Freezing point

High

So that it can’t easily freeze

Resitivity

Low

Rate of corrosion

Low

So that the current high// high heat energy produced Can’t easily rust

Substance R is chosen

Reason: Low density, Freezing point average, resistivity low and rate of corrosion low

14