spm fizik tingkatan 4,5_paper2_20120724090124

7/29/2019 SPM Fizik Tingkatan 4,5_paper2_20120724090124

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SMK KEPONGPHYSICS

Paper 2

Time :

Class : Marks :

This question paper consists ofthree sections: Section A, Section B and Section C.

Kertas soalan ini mengandungi tiga bahagian: Bahagian A, Bahagian B dan Bahagian C.

Section A

Bahagian A

[60 marks]

[60 markah]

Answerall questions in this section.

Jawab semuasoalan dalam bahagian ini.

1. Diagram below shows a boat moving towards a beach. The movement of the waves is shown in Diagram

below.

Rajah di bawah menunjukkan bot bergerak ke arah pantai. Pergerakan ombak ditunjukkan dalam Rajah di

bawah.

Diagram /Rajah

(a) (i) What will happen to boat M when the water waves pass through boat M?

Apakah yang akan berlaku kepada bot M apabila ombak air bergerak melalui botM?

__________________________________________________________________________________

__________________________________________________________________________________

[1 mark/1 markah]

(ii) Give your reason for your answer in (a)(i).Berikan sebab untuk jawapan anda di (a)(i).

__________________________________________________________________________________

__________________________________________________________________________________

[1 mark/1 markah]

(b) (i) State two differences between the water waves at points A and B.

Nyatakan duaperbezaan antara ombak air di titikA dan B.

__________________________________________________________________________________

__________________________________________________________________________________

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[2 marks/2 markah]

(ii) State one similarity between the water waves at points A and B.

Nyatakan satupersamaan antara ombak air di titikA dan B.

__________________________________________________________________________________

__________________________________________________________________________________

[1 mark/1 markah]

(c) State the phenomenon involved at the point D.

Nyatakan fenomena yang terlibat di titikD.

_____________________________________________________________________________________

_____________________________________________________________________________________

[1 mark/1 markah]

(d) If the frequency of the waves is 20 Hz, calculate the velocity of the waves at point B.

Jika frekuensi ombak ialah 20 Hz, hitung halaju ombak di titikB.

[2 marks/2 markah]

2. The circuit below is used to investigate how the resistance of a lamp changes.

Litar di bawah digunakan untuk menyiasat bagaimana rintangan satu lampu berubah.

Diagram /Rajah

(a)Explain how component X allows a set of results to be obtained.

Terangkan bagaimana komponen X membenarkan satu set keputusan diperoleh.

_____________________________________________________________________________________

[2 marks/2 markah]

(b)

The results obtained are used to plot a graph.Keputusan yang diperoleh digunakan untuk memplotkan satu graf.

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Diagram / Rajah

(i) Calculate the resistance of the lamp when the voltage is 4 V.

Hitungkan rintangan lampu itu apabila voltan ialah 4 V.

[3 marks/3 markah]

(ii)Explain how the graph shows that the resistance of the lamp increases as the voltage increases.

Terangkan bagaimana graf itu menunjukkan rintangan lampu itu bertambah apabila voltan bertambah.

____________________________________________________________________________________

_

[1 mark/1 markah]

3. Table A shows three electrical appliances, their ratings and the number of hours they are used in a month.

JadualA menunjukkan tiga alat elektrik, kadar dan bilangan jam pengunaan dalam masa satu bulan.

Electrical appliance

Alat elektrik

Rating

Kadar

Number of hours used

Bilangan jam pengunaan

Television

Televisyon

240 V, 2 000 W 200

Refrigerator

Peti Sejuk

240 V, 1 000 W 100

Fan

Kipas

240 V, 500 W 300

Table A /Jadual A

(a) i. What is meant by the rating 240 V, 2 000 W for a television?

Apakah yang dimaksudkan dengan kadar240V, 2000 Wpada televisyen?

__________________________________________________________________________________

[1 mark/1 markah]

ii. When the television functions normally, what is the current flowing through it?Apabila sebuah televisyon berfungsi secara normal, berapakah nilai arus yang mengalir melaluinya?

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[2 marks/2 markah]

iii. What is the most suitable value of fuse used for the television? Explain your answer.

Berapakah nilai fius yang sesuai digunakan oleh televisyon? Terangkan jawapan anda.

__________________________________________________________________________________

__________________________________________________________________________________

[2 marks/2 markah]

(b) Table B shows the tariff for the use of electrical energy in public housing in one month.

JadualB menunjukkan kadar tarif pengunaan tenaga elektrik untuk rumah kediaman awam dalam masa

satu bulan.

Electrical energy

Tenaga elektrik

Rate per unit

Kadar per unitFirst 100 unit

100 unit pertama

RM 0.20

Second 200 unit

200 unit kedua

RM 0.23

Every additional unit

Setiap pertambahan unit

RM 0.25

Table B /JadualB

Based on Table B, calculate the total cost of using electrical energy for the electrical appliances listed in

Table A.Berdasarkan JadualB, kirakan jumlah kos penggunaan tenaga elektrik untuk peralatan elektrik dalam

JadualA.

[2 marks/2 markah]

4. Diagram A shows the structure of a simple d.c. generator. An e.m.f. is induced when the coil is set into

rotation. The output of the generator is displayed on a CRO as shown in Diagram B. The time base of the

CRO is set at 10 ms cm1 and the Y-gain at 50 mV cm1.Rajah A menunjukkan struktur satu penjana a.t. ringkas.Satu d.g.e. diaruhkan apabila gegelung itu disetkan

ke putaran. Output penjana itu dipaparkan di atas OSKseperti ditunjukkan dalam Rajah B.Dasar masa bagi

OSKdisetkan pada 10 m s cm1 dan gandaan pada 50 mV cm1.

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Diagram A/Rajah A

Diagram B/Rajah B

(a) State the polarity at end R of the solenoid RS.

Nyatakan kutub bagi hujungRsolenoidRS.

_____________________________________________________________________________________

[1 mark/1 markah]

(b) Name the components labelled E and F.

Namakan komponen yang dilabellkan E dan F.

_____________________________________________________________________________________

[2 marks/2 markah]

(c) Which points, (I, II, III and IV), in Diagram B correspond to the instants at which the plane of the coil is

perpendicular to the magnetic field?

Titik yang manakah (I, II, III dan IV) dalam Rajah B bersesuaian dengan saat di mana satah gegelung

adalah berserenjang dengan medan magnet?

_____________________________________________________________________________________

[1 mark/1 markah]

(d) Find the peak voltage and frequency of the output of the generator.Cari voltan puncak dan frekunesi bagi voltan output penjana itu.

_____________________________________________________________________________________

[1 mark/1 markah]

(e) Describe what happens to the peak voltage and frequency of the output of the generator if

Terangkan apa yang berlaku kepada voltan puncak dan frekuensi bagi output penjana itu jika

(i) the speed of rotation of the coil is increased.

laju putaran gegelung ditambahkan.

__________________________________________________________________________________

[1 mark/1 markah]

(ii) the resistance of the rheostat is increased.

rintangan reostat ditambahlan.

__________________________________________________________________________________

[1 mark/1 markah]

(f) Name one alternation to the structure to change the d.c. generator to a.c. generator.

Namakansatugantian struktur yang mengubahkan penjana a.t. kepada penjana a.u.

_____________________________________________________________________________________

[1 mark/1 markah]

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5.

DIAGRAM /RAJAH

Diagram above shows the arrangement of four diodes in a bridge rectifier for a step-down transformer used

for full-wave rectification.

Rajah di atas menunjukkan susunan empat diod dalam bentuk tetimbang bagi suatu transformer injak turun

yang digunakan untuk rektifi kasi gelombang penuh.

(a) Why is the circuit not connected directly to the 240 V a.c. power supply?

Mengapakah litar itu tidak boleh disambung terus ke bekalan elektrik240 V a.u.?

_____________________________________________________________________________________

_____________________________________________________________________________________

[1 mark/1 markah]

(b) Which of the four diodes shown in the circuit is connected in the reverse direction?

Antara empat diod yang ditunjukkan dalam litar, manakah yang disambung terbalik?

_____________________________________________________________________________________

_____________________________________________________________________________________[1 mark/1 markah]

(c) If the mistake in the connection in (b) is corrected, sketch the shape of the trace observed on the

CRO screen when the time-base is on.

Jika kesilapan penyambungan dalam (b) dibetulkan, lakarkan bentuk surih yang diperhatikan pada skrin

OSKapabila dasar masa dihidupkan.

[1 mark/1 markah]

(d) (i) If a student connects a capacitor in parallel across a resistor R, sketch the shape of the trace obtained.

Jika seorang pelajar menyambungkan satu kapasitor secara selari dengan perintangR, lakarkan

bentuk surih yang diperoleh.

[1 mark/1 markah]

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(ii) What is the function of the capacitor?

Apakah fungsi kapasitor itu?

__________________________________________________________________________________

[1 mark/1 markah]

(e) Sketch the shape of the trace observed on the CRO screen if diode D3 malfunctions.

Jika diodD3telah rosak, lakarkan bentuk surih yang diperhatikan pada skrin OSK.

[1 mark/1 markah]

6. The signals in Diagram A are applied to inputs A and B of the logic gate in Diagram B.

(Note: 5 V denotes a high state of voltage and 0 V denotes a low state of voltage.)

Isyarat-isyarat dalam Rajah A diaplikasikan kepada inputA dan B bagi gek logik dalam Rajah B.(Perhatian: 5 V menandakan satu keadaan voltan tinggi dan 0 V menandakan satu keadaan voltan rendah.)

Diagram A/Rajah A Diagram B/Rajah B

Diagram B/Rajah B

(a) (i) Name the gate shown in Diagram B.

Namakan get yang ditunjukkan dalam Rajah B.

[1 mark/markah]

(ii) Draw the waveform of the output C of the logic gate.

Lukiskan bentuk gelombang bagi outputC bagi get logik itu.

[2 marks/markah]

(b) Box X in Diagram C represents an unknown logic gate.

The variations of input voltages and the corresponding output voltage are shown in Diagram D.

KotakX dalam Rajah C mewakili satu get logik yang tidak diketahui. Perubahan voltan input dan voltan

output yang sepadan ditunjukkan dalam Rajah D.

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Diagram C/Rajah C

Diagram D/Rajah D

(i) What is X?

Apakah X?

[1 mark/markah]

(ii) Construct a truth table for X.

Binakan jadual kebenaran bagi X.

[2 marks/markah]

7. A radioactive substance X of mass number 234 and atomic number 91 undergoes decay to emit a radioactive

particle and is transformed into another nuclide. When the particle passes through a magnetic field pointing

into a piece of paper, it is deflected as shown in Diagram below.

Satu bahan radioaktifX dengan nombor jisim 234 dan nombor atom 91 mengalami reputan untuk memancarsatu zarah radioaktif dan ditukarkan kepada nuklid yang lain. Apabila zarah-zarah itu melalui satu medan

magnet yang menuju ke dalam kertas, zarah-zarah itu terpesong seperti yang ditunjukkan dalam Rajah di

bawah.

Diagram /Rajah(a) What type of radioactive particle is emitted by X?

Apakah jenis zarah radioaktif yang dipancarkan oleh X?

[1 mark/markah]

(b) Write one equation to show the decay of X. Use the symbol Y to represent the daughter nuclide. What is

the neutron number of the daughter nuclide Y?

Tuliskan satupersamaan untuk menunjukkan reputan X. Gunakan simbolY untuk mewakili anak nuklid.

Apakah nombor neutron bagi anak nuklidY?

[2 marks/markah]

(c) When the activity of radiation of X is recorded, a curve is obtained as shown in Diagram below.

Apabila aktiviti bagi sinaran X dicatatkan, satu lengkungan diperoleh seperti yang ditunjukkan dalam

Rajah di bawah.

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Diagram /Rajah

(i) Suggest one device which is suitable for detecting the activity of the radiation.

Cadangkansatualat yang sesuai untuk mengesan aktiviti bagi sinaran itu.

[1 mark/markah]

(ii) Why are the points not exactly on the smooth curve?

Mengapakah titik-titik itu tidak berada tepat di atas lengkungan itu?

[1 mark/markah]

(iii

)

Find the half-life of X as shown by the above diagram.

Cari setengah hayat bagi X seperti yang ditunjukkan oleh rajah di atas.[1 mark/markah]

(d) (i) The radioactive sample X is used as a tracer to investigate the digestive system of a patient by a

doctor. Explain whether it is suitable by considering its half-life and the type of radiation.

Sampel radioaktifX digunakan sebagai penyurih untuk menyiasat sistem penghadaman seorang

pesakit oleh doktor. Terangkan sama ada ia sesuai dengan mengambil kira setengah hayatnya dan

jenis sinaran.

[1 mark/markah]

(ii) Explain your answer.

Terangkan jawapan anda.

[2 marks/markah]

8. (a) Diagram A shows the arrangement of radioactive fuel rods in a nuclear reactor.

Rajah A menunjukkan susunan rod bahan bakar radioaktif dalam satu reaktor nuklear.

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Diagram A/Rajah A

Diagram B/Rajah B

(i) The nuclear reactor is surrounded by steel inside a thick concrete shield. Explain why.

Reaktor nuklear itu dikelilingi oleh keluli dalam satu perisai konkrit yang tebal. Terangkan mengapa.

__________________________________________________________________________________

[2 marks/2 markah]

(ii) State two harmful effects of radiation on humans.Nyatakanduakesan sinaran yang berbahaya kepada manusia.

__________________________________________________________________________________

[2 marks/2 markah]

(iii

)

Explain why precautions are taken for storing the radioactive fuel rods when they are removed from a

reactor.

Terangkan mengapa langkah-langkah berjaga diambil untuk menyimpan rod bahan bakar radioaktif

itu apabila dialihkan dari reaktor itu.

__________________________________________________________________________________

[1 mark/1 markah](b) Diagram B shows the nuclear reaction taking place in a reactor.

Rajah B menunjukkan tindak balas nuklear yang berlaku dalam satu reaktor.

(i) What type of nuclear reaction is shown in the diagram?

Apakah jenis tindak balas nuklear yang ditunjukkan dalam rajah itu?

__________________________________________________________________________________

[1 mark/1 markah]

(ii) What type of energy is transferred to barium and krypton in this reaction?

Apakah jenis tenaga yang dipindahkan ke barium dan kripton dalam tindak balas ini?

__________________________________________________________________________________

[1 mark/1 markah]

(iii

)

Explain how the energy produced in this reaction can be used to generate electricity in a nuclear power

plant.

Terangkan bagaimana tenaga dihasilkan dalam tindak balas ini boleh digunakan untuk menjana

elektrik dalam satu loji kuasa nuklear.

__________________________________________________________________________________

__________________________________________________________________________________

__________________________________________________________________________________

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__________________________________________________________________________________

__________________________________________________________________________________

[3 marks/3 markah]

Section B

Bahagian B

[20 marks]

[20 markah]

Answer any one question from this section.

Jawab mana-mana satusoalan daripada bahagian ini.

9. Diagram A shows a cork floating on the water surface in a ripple tank. It is found that the cork oscillates up

and down when a vibrating plastic sphere is dipped into the water surface. Diagram B shows a candle flame

that is displaced from side to side when it is placed in front of a blasting loudspeaker.Rajah A menunjukkan satu gabus terapung di permukaan air suatu tangki riak. Didapati gabus bergetar

turun-naik apabila permukaan air dikacau oleh suatu pencelup sfera yang bergetar. Rajah B menunjukkan

api lilin yang disesarkan ke kiri dan ke kanan apabila diletakkan di hadapan suatu pembesar suara yang

berbunyi.

Diagram A/Rajah A

Diagram B/Rajah B

(a) (i) Explain the meaning of oscillation.

Terangkan maksud getaran.

[1 mark/1 markah]

(ii) Based on the observations made on Diagram A and B, state the characteristics that are common and

that are contrasting between the two situations. Hence, relate the characteristics of the oscillations ofthe cork and the candle flame to deduce a relevant physics concept.

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Berdasarkan pemerhatian pada Rajah A dan B, nyatakan ciri-ciri sepunya dan berbeza bagi kedua-

dua situasi itu. Seterusnya, hubungkaitkan ciri-ciri itu untuk membuat satu kesimpulan tentang konsep

fizik yang berkaitan.

[5 marks/5 markah]

(b) A source of sound is placed at X, the centre of a wall in a room PQRS measuring 40 m 40 m.

Suatu sumber bunyi diletakkan pada titik tengah Xsebuah dinding pada sebuah bilikPQRSyang

berukuran 40 m 40 m.

Diagram C /Rajah C

(i) On Diagram C, draw the path of the sound wave from X, where it is transmitted , until it returns to X

after reflections by each of the three walls.

Lukiskan lintasan gelombang bunyi yang dipancarkan dari X dan kembali kepada Xselepas

dipantulkan oleh setiap tiga dinding yang lain itu.

[1 mark/1 markah]

(ii) State two reasons why the sound returned to X is less loud than the sound sent out from X.

Nyatakanduasebab mengapa kenyaringan bunyi yang kembali kepada X kurang daripada

kenyaringan bunyi yang dipancarkan.

[3 marks/3 markah]

(c) Diagram D shows one of the uses of ultrasound . It is used to check the condition of the foetus in the

mothers womb.The ultrasound used is usually of high frequency, about 100 times higher than the

maximum frequency that is audible to humans.Rajah D menunjukkan kegunaan gelombang ultrasonik untuk mengesan keadaan fetus dalam kandungan

ibu. Gelombang ultrasonik yang biasa digunakan mempunyai frekuensi lebih kurang100 kali lebih tinggi

daripada frekuensi maksimum yang boleh didengar oleh manusia.

Diagram D /Rajah D

(i) Determine the approximate frequency of the ultrasound used.

Tentukan nilai frekuensi anggaran ultrasonik yang digunakan.

[1 mark/1 markah]

(ii) Explain briefly the functions of the transmitter P and then receiver R in the process of foetus

inspection.

Terangkan secara ringkas fungsi pemancarP dan penerima Rdalam proses pemeriksaan fetus.

[2 marks/2 markah]

(iii)

How does the ultrasound distinguish between the tissues and bony parts of the foetus?Bagaimanakah gelombang ultrasonik dapat membezakan antara bahagian tisu dengan tulang dalam

badan fetus itu?

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[2 marks/2 markah]

(iv)Give one reason why X-rays are not suitable for foetus inspection.

Berikan satusebab mengapa sinar-X tidak digunakan untuk pemeriksaan fetus.

[2 marks/2 markah]

(v) State three differences between X-rays and ultrasound.

Nyatakantigaperbezaan antara sinar-X dengan gelombang ultrasonik.

[3 marks/3 markah]

10. The national grid is an important system which ensures that the electric power supply is always continuous.

After electrical energy is generated at the power generator, the electrical energy will be transferred through a

few substations that contain transformers before reaching the consumers.

Table A shows the current and potential difference of the electrical energy before and after passing through

substation A during the transfer of electrical energy.

Sistem rangkaian grid nasional merupakan satu sistem yang penting untuk memastikan bekalan kuasa elektrik

adalah berterusan. Selepas tenaga elektrik dijanakan di stesen jana kuasa, tenaga elektrik itu akan dipindah

melalui beberapa substesen yang mengandungi transformer sebelum sampai kepada penggunanya.

JadualA menunjukkan arus dan beza keupayaan tenaga elektrik sebelum dan selepas melalui suatu substesen

Asemasa penghantaran tenaga elektrik.

Table A/JadualA

Table B shows the current and the potential difference of the electrical energy before and after passing

through substation B during the reception of electrical energy by the consumers.JadualB menunjukkan arus dan beza keupayaan tenaga elektrik sebelum dan selepas melalui suatu substesen

Bsemasa penerimaan tenaga elektrik oleh pengguna.

Table B/JadualB(a) (i) What is the meaning of potential difference?

Apakah yang dimaksudkan dengan beza keupayaan?

[1 mark/markah]

(ii) By using only the information in Tables A and B, compare the characteristics of the power of the

electric power that is transmitted and received by the consumers. Then state the relationship between

current and potential difference when transmitting and receiving electrical energy.

Menggunakan hanya maklumat dalam JadualA dan B, bandingkan ciri-ciri kuasa elektrik yang

dihantar dan diterima oleh pengguna. Seterusnya nyatakan hubungan antara arus dengan beza

keupayaan semasa penghantaran dan penerimaan tenaga elektrik

[5 marks/markah]

(b) Generating electrical power involves the use of renewable sources and nonrenewablesources of energy. By using suitable examples, compare the 2 types of sources.

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Penjanaan kuasa elektrik melibatkan penggunaan sumber tenaga yang boleh diperbaharui dan sumber

tenaga yang tidak boleh diperbaharui. Dengan menggunakan contoh-contoh yang sesuai, bandingkan

kedua-dua jenis sumber itu.

[4 marks/markah]

(c) When transferring and receiving electrical energy, poles such as those

shown in Diagram below play an important role.

Semasa penghantaran dan penerimaan tenaga elektrik, tiang-tiang seperti pada Rajah di bawah

memainkan peranan yang sangat penting.

Diagram /Rajah

By using your knowledge on the transfer of electrical energy and Diagram above, explain;

Menggunakan pengetahuan anda tentang penghantaran tenaga elektrik dan Rajah di atas, terangkan;

(i) the safety features that are needed to build the poles,

ciri-ciri keselamatan yang diperlukan untuk membina tiang,

(ii) the properties of the cables that are used.

ciri-ciri kabel yang digunakan.

[10 marks/markah]

Section C

Bahagian C

[20 marks]

[20 markah]

Answer any one question from this section.

Jawab mana-mana satusoalan daripada bahagian ini.

11. Diagram A shows a heating element in an electric kettle. Table A shows the characteristics of some materials

that can be used for making a heating element.

Rajah A menunjukkan satu unsur pemanas dalam sebuah cerek elektrik. JadualA menunjukkan ciri-ciri

bahan yang boleh digunakan untuk membuat unsur pemanas.

Diagram A/Rajah A

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Table A/JadualA

(a) i. What is meant by resistance?

Apakah yang dimaksudkan dengan rintangan?

[1 mark/1 markah]

ii. You are assigned to investigate the characteristics of the materials in Table A for use in the making of a

heating element as shown in Diagram A.

Anda ditugaskan untuk mengkaji ciri-ciri bahan dalam JadualA untuk digunakan bagi membuat unsurpemanas seperti pada Rajah A.

Explain the suitability of each characteristic in Table A and then determine the most suitable material

for making into a heating element. State the reasons for your choice.

Terangkan kesesuaian setiap ciri dalam JadualA dan seterusnya tentukan bahan yang paling sesuai

untuk membuat unsur pemanas itu. Berikan sebab-sebab untuk pilihan anda.

[10 marks/10 markah]

(b) Diagram B shows a circuit for determining the electromotive force and the internal resistance of a dry cell.

Rajah B menunjukkan satu litar untuk menentukan daya gerak elektrik dan rintangan dalam sel bagi satu

sel kering.

Diagram B/Rajah B

i. Sketch a graph of potential difference against current for the circuit. Use your graph to explain how the

electromotive force and the internal resistance of a dry cell can be determined.

Lakarkan graf beza keupayaan melawan arus bagi litar itu. Gunakan graf anda untuk menerangkan

bagaimana daya gerak elektrik dan rintangan dalam sel kering dapat ditentukan.

[4 marks/4 markah]

ii. The total resistance for both the resistors and rheostat in the circuit is 5 ohm. Calculate the current in

the circuit if the potential difference before the switch is on and after the switch is on are 6 V and 5 V

respectively. Then, calculate the internal resistance of the dry cell.

Jumlah rintangan bagi kedua-dua perintang dan reostat dalam litar itu ialah 5 ohm.Hitungkan arus

dalam litar jika beza keupayaan sebelum suis ditutup dan selepas suis ditutup masing-masing ialah 6 Vdan 5 V. Seterusnya, kirakan rintangan dalam sel kering itu.

[5 marks/5 markah]

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12. Diagram below shows a sign indicating Danger! Ionising Radiations commonly seen outside a nuclear and

radioactivity laboratory.

Rajah di bawah menunjukkan suatu tanda yang menyatakan Bahaya! Sinaran Pengionan yang biasa

dilihat di luar suatu makmal Nuklear dan Radioaktif.

Diagram /Rajah

(a) (i) What is meant by radioactivity?

Apakah yang dimaksudkan dengan radioaktiviti?

[1 mark/1 markah]

(ii) Name the three types of ionizing radiation produced by a radioactive source.Berikan nama tiga jenis sinaran pengionan yang dihasilkan oleh suatu sumber radioaktif.

[2 marks/2 markah]

(iii

)

State the nature of each type of ionizing radiation given in your answer in (a)ii.

Nyatakan ciri asli setiap jenis sinaran pengionan dalam jawapan anda di (a)(ii).

[2 marks/2 markah]

(b) In a hospital, a doctor intends to use a radioisotope as a tracer to detect blood clots in a patients leg. Table

below shows the characteristics of five radioisotopes.

Di sebuah hospital, seorang doktor ingin menggunakan suatu radioisotop sebagai penyurih untuk

mengesan pembekuan darah pada kaki seorang pesakit.

Jadual di bawah menunjukkan ciri-ciri bagi lima radioisotop itu.

TABLE /JADUAL

(i) Explain the suitability of the characteristics of the radioisotopes to be used as medical tracers to detect

blood clots.

Terangkan kesesuaian ciri-ciri radioisotop itu untuk digunakan sebagai penyurih perubatan untuk

mengesan kedudukan pembekuan darah.

(ii) Hence determine the most suitable choice of the radioisotope and give reasons for your choice.

Dengan demikian, tentukan radioisotop yang paling sesuai dan berikan sebab bagi pemilihananda.

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[10 marks/10 markah]

(c) Diagram below shows the activity of a certain radioisotope, X.

Rajah di bawah menunjukkan aktiviti bagi suatu radioisotop X.

Diagram /Rajah

(i) Estimate the half-life of radioisotoped X.

Anggarkan setengah-hayat bagi radioisotop X.[1 mark/1 markah]

(ii) A freshly prepared sample of radioisotope X has an initial activity of 3 200 counts per minute.

How long does it take for its activity to be reduced to 400 counts per minute?

Suatu radioisotop Xyang baru disediakan mempunyai aktiviti 3 200 bilangan per minit.

Berapa lamakah yang diambil untuk aktivitinya berkurang kepada 400 bilangan per minit?

[2 marks/2 markah]

(iii

)Radioisotope decays to a nuclide, Y, by alpha particle emission.

Write an equation to represent this radioactive decay.

Radioisotop mereput menjadi nuklidY dengan memancarkan zarah alfa.

Tuliskan satu persamaan untuk mewakili pereputan radioaktif ini. [2 marks/2 markah]

SMK KEPONG Jawapan

SPM Fizik Tingkatan 4,5 - SOALAN FORM 5 PAPER 2 Kertas 2

1. (a) (i) Boat M will be moving up and down.

BotM bergerak ke atas dan ke bawah.

(ii) The molecules of water move perpendicular to the direction of propagation of the

water.

Molekul air bergerak berserenjang dengan arah perambatan air.

(b) (i) The wavelength of water waves is shorterat A.

Panjang gelombang air lebih pendek di A.

The velocity of water waves is slower at A.

Halaju air lebih perlahan di A.

(ii) Has the same frequency

Mempunyai frekuensi yang sama

(c) Diffraction

Pembelauan

(d)

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2. (a) Component X can vary its resistance.

This affects the current in the circuit.When the resistance is low, the current fl owing in the circuit is high.

(b) (i) When V = 4 V,

I = 1.6 A

Using formula, V = IR

4 = (1.6)(R)

R = 2.5 ohm

(ii) T he resistance is inversely proportional to gradient the gradient. When the voltage

increases,

the gradient decreases, the resistance increases.

3. (a) i. Television needs 240 V source to function normally and the power of the television

is 2 000 W.

Televisyen memerlukan sumber240 V untuk berfungsi dengan normal dan kuasa

televisyen ialah 2000 W.

iii. A current of 9 A exceeds the normal situation. The fuse will melt and break theelectric circuit/electricity immediately.

Arus sebanyak9 A melebihi situasi yang normal. Fius akan mencair dan memutuskan

litar elektrik/ arus elektrik dengan segera.

(b) The use of electrical energy

Penggunaan tenaga elektrik

= 2 kW 200 h + 1 kW 100 h + 0.5 kW 300 h

= 400 kWh + 100 kWh + 150 kWh

= 650 kWh

The cost of electricity

Kos penggunaan elektrik

= 100 RM 0.20 + 200 RM 0.23 + 350 RM 0.25

= RM 153.50

4. (a) North

(b) E: half-ring

F: carbon brush

(c) I and III

(d) Peak voltage = 50 mV

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(e) (i) Peak voltage increases. Frequency of the output increases.

(ii) Peak voltage decreases. Frequency of the output remains unchanged.

(f) Use a slip-ring instead of the half-ring.

5. (a) High voltage will cause malfunction of the diode

Voltan yang terlalu tinggi akan merosakkan diod.

(b) D4

(c)

(d) i.

ii. Acts as a current regulator/smoother

Bertindak sebagai perata arus.

(e)

6. (a) i. OR gate

ii.

(b) i. NOR gate

ii.

7. (a) X emits particles.

(b)

Neutron number of Y = 234 92 = 142

(c) i. GM tube

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ii. Radiation has a random nature.

iii. Half-life = 3 hours

(d) i. The half-life is suitable to be used since it is short enough to reduce the harmful

effect and long enough

for the doctor to make diagnosis.

ii. The type of radiation, b, is not suitable since the penetrating power of b is not largeenough to pass to

the outside of the human body for detection.

8. (a) (i) To prevent the escape of radioactive rays and keep radiation in the radiator. Alpha

and beta radiation

cannot penetrate through thick concrete and gamma radiation can be reduced by thick

concrete

(ii) Can cause cell mutation which results in cancer

Severe skin burns

Damage to the reproductive cells

(iii) Radioactive fuel rods contain dangerous radioactive wastes which emit harmfulradioation rays

(b) (i) Nuclear fission

(ii) Heat energy

(iii) Nuclear fission of uranium produces a high amount of heat energy

The heat liberated heats up the surrounding water in the nuclear power plant

Heat changes water to steam

The steam generated drives the turbines which turn the electrical generator

Electricity is generated

9. (a) (i) An oscillation is a to-and-fro motion along a fixed path.

(ii) 1. The sphere and the candle flame are in vibration. [1 m]2. Vibrating sphere produces water waves. [1 m]

3. Water waves transfer energy from the sphere to the ball. [1 m]

4. The vibrating cone of the speaker produces sound waves. [1 m]

5. Sound waves transfer energy from the cone to the candle flame. [1 m]

6. Vibrations of water waves are vertical, perpendicular to the direction of wave motion.

[1 m]

7. Vibrations of sound waves are horizontal, parallel to the direction of wave motion. [1

m]

8. Physics concept: wave

A wave transfers energy from the source to points around it by vibrations in the medium.

(b) (i)

[1 m]

(ii) 1. On each reflection, part of the sound energy is absorbed by the wall. [1 m]2. The energy of sound decreases with distance travelled. [1 m]

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3. The loudness of sound depends on the energy of the sound wave. [1 m]

(c) (i) Maximum audible frequency, 0 = 20 000 Hz [1 m]

Frequency of ultrasound used, = 1000

= 100 20 000

= 2.0 106 Hz [1 m]

(ii) 1. Transmitter P emits ultrasound downwards to the foetus. [1 m]2. Detector R receives the ultrasound reflected by the various parts of the foetus. [1 m]

(iii) The soft tissues of the foetus absorb most of the incident ultrasound, reflect very

little. The bony

parts will absorb very little, but reflect most of the ultrasound. The reflected ultrasound

will produce an

image of contrasting brightness. [2 m]

(iv) X-rays have high ionization power, can damage and kill the cells of the foetus. [1 m]

(v) Differences

[3 m]

10. (a) i. The potential difference between 2 points is the work done to move a coulomb of

charge from onepoint to another. [1 m]

ii. At the power generator system, the electrical power produced is in the form of low

potential difference. [1 m]

After passing through substation A, the potential difference of electrical power

increases while the

current decreases so that the amount of power lost can be reduced. [1 m]

Before reaching the consumers, the potential difference is lowered so that it is suitable

for the

consumers. [1 m]

Potential difference can be increased by using a step-up transformer can be reduced by

using astepdown transformer. [1 m]

When the potential difference is increased, the value of the current will decrease. This

is also

the same when potential difference is decreased, value of current will increase. [1 m]

(b) Examples of non-renewable sources are coal, natural gas and nuclear energy. [1 m]

These sources will be depleted if they are used frequently and will normally pollute the

environment.

[1 m]

Examples of renewable sources are hydroelectric power, solar energy, biomass and

wind energy. [1 m] These sources will not be depleted and their usage usually will not pollute the

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environment. [1 m]

(c) i. The poles need to be earthed. [1 m]

This is to carry the extra charges straight to the earth.

Glass or porcelain is fixed at the connecting areas of the cable at the poles. [1 m]

so that the metal poles did not touch the electric cable directly. This will cause the

poles to be atpotential earth condition and is safe to touch. [1 m]

Red light is fixed at high poles. [1 m]

This is to give warning or signal for helicopters or aeroplanes so that collision does not

happen. [1 m]

ii. Aluminium cable that is cheap and has low resistance is chosen. [1 m]

So that the amount of power lost when transferring can be reduced. [1 m]

The cable must be insulated. [1 m]

So that it is not dangerous when kites or other things got stuck at the cable. [1 m]

11. (a) i. Resistance is the ratio of potential difference to current.

Rintangan adalah nisbah beza keupayaan kepada arus.ii. A high melting point

Takat lebur yang tinggi

So that the heating element does not melt easily at high temperatures

Supaya elemen pemanasan tidak melebur dengan mudah pada suhu yang tinggi

A low resistance

Rintangan yang rendah

So that a larger current can flow through it. This will produce a better heating effect.

Supaya arus yang lebih besar boleh mengalir melaluinya. Ini akan menghasilkan suatu

kesan pemanasan yang lebih baik

Does not break easily at high temperatures

Tidak berpecah dengan mudah pada suhu yang tinggi So that the heating element can last longer and is not spoilt at high temperatures.

Supaya elemen pemanasan boleh tahan lebih lama dan tidak rosak pada suhu yang

tinggi

Not easily oxidised.

Tidak mudah dioksidakan

So that water that is boiled is free from chemicals.

Supaya air yang dididihkan adalah bebas daripada bahan kimia

Material P is chosen.

Bahan P dipilih.

This is because material P has a high boiling point, low resistance, not easy to break at

high temperatures and is not very easily oxidised.Ini disebabkan bahan P mempunyai takat didih yang tinggi, rintangan rendah, tidak

mudah pecah pada suhu yang tinggi dan tidak mudah sangat dioksidakan

(b) i.

Electromotive force is determined by extending the graph to cut the y-axis (When x =

0)

Daya gerak elektromagnet ditentukan dengan memanjangkan graf untuk memotong

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pada paksi-y (apabila x = 0)

Internal resistance of the dry cell is determined by the gradient of the graph.

Rintangan dalam sel kering ditentukan oleh kecerunan graf

ii. Potential difference that flows across the resistor when the switch is switched on is

V = 5 V,

Beza keupayaan yang merentasi perintang apabila suis dipasang pada V= 5V,with this the current that flows in the circuit is

dengan arus ini yang mengalir dalam litar ialah

I = _V _ = _ 5

R 10

= 0.5 A

The potential difference that is lost in the dry cell is

Beza keupayaan yang hilang dalam sel kering itu ialah V = 6 V -5 V = 1V

The internal resistance of the dry cell is/

Rintangan dalam sel kering itu ialah r

12. (a) (i) Radioactivity is a process where an unstable nucleus decays spontaneously to

become a more

stable nucleus by emitting radioactive radiation.

Keradioaktifan adalah proses di mana nukleus tak stabil mereput secara spontan

menjadi nukleus

yang lebih stabil dengan memancar sinaran radioaktif.

(ii) Alpha particles, beta particles, gamma radiation.

Zarah alfa, zarah beta, sinaran gama.

(iii) An alpha particle is a helium nucleus.

Zarah alfa adalah nukleus helium.A beta particle is a fast moving electron.

Zarah beta adalah elektron yang bergerak cepat.

Sinaran gamma radiation is an electromagnetic radiation.

Sinaran gama adalah sinaran elektromagnet.

(b) (i) The radioisotope must be in the liquid state, so that it is convenient to be injected

into the bloodstream.

Beta or low energy gamma rays are suitable, as they can penetrate body tissues.

Energy of the radiation emitted must be low so that it does not damage/kill the living

cells in the body.

Half-life must be short, but long enough for doctors to measure the activity of the

injected radioisotope.

Radioisotop harus dalam keadaan cecair, supaya ia adalah sesuai untuk disuntik ke

dalam aliran

darah. Beta atau sinar gama yang bertenaga rendah adalah sesuai, sebab boleh

menembusi tisu

badan. Tenaga daripada sinaran yang dipancarkan harus rendah supaya ia tidak

merosakkan/membunuh selsel hidup badan. Setengah hayat harus pendek, tetapi cukup

masa untuk

doktor mengukur aktiviti bagi radioisotop yang disuntik.

(ii) Best choice = iodine-123, as it is in liquid state, emits low energy gamma rays andhas a half-life

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of 13.2 hours which is long enough for medical investigation, but will be harmless to the

patient

after a few days.

Pilihan yang paling baik= Iodin-123,sebab ia adalah dalam keadaan cecair,

memancarkan gama

yang bertenaga rendah dan mempunyai setengah hayat13.2jam yang cukup panjang

untukpenyiasatan perubatan. tetapi akan berbahaya kepada pesakit selepas beberapa hari.

(c) (i) Half-life is the time taken for activity to decrease to half its original value.

Setengah hayat adalah masa yang diambil untuk aktiviti berkurang kepada setengah

nilai asalnya.

At t = 0, activity/aktiviti = 2000 Cpm.

Pada t = 10 min, activity/aktiviti = 1000 Cpm.

Hence, half life = 10 minutes

Maka, setengah hayat= 10 minit

(ii)

(iii)

spm fizik tingkatan 4,5_paper2_20120724090124

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