SainsScience

Print questions onlyCetak soalan sahaja Print with answersCetak dengan skema Print answer key onlyCetak kunci jawapan sahaja Practice shows answers as you go. Exam times you and hides answers until you submit.Latihan menunjukkan jawapan semasa menjawab. Peperiksaan menetapkan masa dan menyembunyikan jawapan sehingga dihantar.

1

QuestionSoalan 1

Seorang doktor di hospital menerangkan sistem saraf manusia kepada pelajar perubatan. Antara berikut, yang manakah sebahagian daripada sistem saraf periferi?A doctor at a hospital explains the human nervous system to medical students. Which of the following is part of the peripheral nervous system?

• AOtakBrain
• BSaraf tunjangSpinal cord
• CSaraf kraniumCranial nerves
• DMedula oblongataMedulla oblongata

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C

The central nervous system is the brain (including the medulla oblongata) and the spinal cord. The peripheral nervous system is made up of the 12 pairs of cranial nerves and the 31 pairs of spinal nerves.

For the teacherUntuk guru: RememberingMengingat, lowrendah difficultyaras lowrendah, ChapterBab 1, standard 1.1.1

TextbookBuku teks p.ms. 4

2

QuestionSoalan 2

Akar sebatang pokok di tepi jalan tumbuh ke arah sebatang paip air yang bocor di bawah tanah. Apakah jenis tindak balas ini?The roots of a tree beside the road grow towards a leaking water pipe under the ground. What type of response is this?

• AHidrotropisme positifPositive hydrotropism
• BHidrotropisme negatifNegative hydrotropism
• CGeotropisme positifPositive geotropism
• DGerakan nastiNastic movement

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A

Water is the stimulus and the roots grow towards it, so the response is positive hydrotropism. Geotropism is a response to gravity, and a nastic movement is fast and does not depend on the direction of the stimulus, whereas growth towards the pipe is slow and directional.

For the teacherUntuk guru: UnderstandingMemahami, lowrendah difficultyaras lowrendah, ChapterBab 1, standard 1.3.1

TextbookBuku teks p.ms. 33

3

QuestionSoalan 3

Di pameran sains, Haziq menarik tangannya daripada plat pemanas yang panas dalam masa 0.1 s. Dia kemudian mengambil masa 0.25 s untuk menekan butang berhenti apabila lampu merah menyala. Mengapakah tindak balas kedua mengambil masa yang lebih lama?At the science fair, Haziq pulls his hand away from a hot plate in 0.1 s. He then takes 0.25 s to press a stop button when a red light comes on. Why does the second response take longer?

• ATangan mempunyai lebih banyak reseptor daripada mata.The hand has more receptors than the eye.
• BImpuls untuk menarik tangan lebih kuat daripada impuls untuk menekan butang.The impulse for pulling the hand away is stronger than the impulse for pressing the button.
• CImpuls untuk menekan butang sampai ke efektor sebelum sampai ke reseptor.The impulse for pressing the button reaches the effector before it reaches the receptor.
• DImpuls untuk menekan butang melalui otak, iaitu laluan yang lebih panjang daripada laluan refleks melalui saraf tunjang.The impulse for pressing the button passes through the brain, a longer pathway than the reflex pathway through the spinal cord.

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D

Pulling the hand from a hot plate is a reflex: the impulse goes through the spinal cord only. Pressing the button is a voluntary action: the impulse must be interpreted by the brain, a longer pathway. The strength of the impulse (B) and the number of receptors (A) do not explain the delay, and an impulse always goes from the receptor to the effector (C).

For the teacherUntuk guru: AnalysingMenganalisis, hightinggi difficultyaras hightinggi, ChapterBab 1, standard 1.1.2

TextbookBuku teks p.ms. 7

4

QuestionSoalan 4

Seorang pendaki tinggal di sebuah kem pada ketinggian 3 500 m selama beberapa minggu, di mana udara mengandungi kurang oksigen. Apakah perubahan yang berlaku dalam badannya?A mountaineer stays at a camp at a height of 3 500 m for several weeks, where the air has less oxygen. What changes happen in her body?

• ABilangan sel darah merah berkurang.The number of red blood cells decreases.
• BLebih banyak sel darah merah dihasilkan dan oksigen dibebaskan daripada oksihemoglobin dengan lebih mudah.More red blood cells are made and oxygen is released from oxyhaemoglobin more easily.
• CKarbon monoksida bergabung dengan hemoglobin membentuk karboksihemoglobin.Carbon monoxide combines with haemoglobin to form carboxyhaemoglobin.
• DBilangan alveolus bertambah dengan banyak.The number of alveoli increases greatly.

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B

At high altitude less oxygen reaches the cells, so the body makes more red blood cells and releases oxygen from oxyhaemoglobin more easily. The number of red blood cells does not fall (A), carboxyhaemoglobin comes from carbon monoxide in smoke and exhaust (C), and the number of alveoli does not change (D).

For the teacherUntuk guru: ApplyingMengaplikasi, mediumsederhana difficultyaras mediumsederhana, ChapterBab 2, standard 2.2

TextbookBuku teks p.ms. 55

5

QuestionSoalan 5

Antara berikut, yang manakah menunjukkan pertukaran gas dalam daun sebatang pokok pada waktu malam?Which of the following shows the gaseous exchange in the leaves of a plant at night?

• AMenyerap karbon dioksida dan membebaskan oksigenTakes in carbon dioxide and gives out oxygen
• BMenyerap oksigen dan membebaskan karbon dioksidaTakes in oxygen and gives out carbon dioxide
• CMenyerap oksigen dan membebaskan oksigenTakes in oxygen and gives out oxygen
• DTidak menyerap atau membebaskan sebarang gasDoes not take in or give out any gas

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B

All plants respire day and night, but photosynthesis stops in the dark. At night the plant takes in oxygen and gives out carbon dioxide only. Option A describes photosynthesis in the light.

For the teacherUntuk guru: RememberingMengingat, lowrendah difficultyaras lowrendah, ChapterBab 2, standard 2.5.1

TextbookBuku teks p.ms. 68

6

QuestionSoalan 6

Seorang jururawat mengira 17 denyutan nadi seorang pesakit dalam masa 15 saat. Berapakah kadar denyutan nadi pesakit itu?A nurse counts 17 pulses of a patient in 15 seconds. What is the pulse rate of the patient?

• A1.1 denyutan seminit1.1 beats per minute
• B17 denyutan seminit17 beats per minute
• C255 denyutan seminit255 beats per minute
• D68 denyutan seminit68 beats per minute

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D

There are four 15-second periods in one minute, so the pulse rate = 17 × 4 = 68 beats per minute. 255 multiplies by 15, 1.1 divides by 15 and 17 forgets to change to one minute.

For the teacherUntuk guru: ApplyingMengaplikasi, lowrendah difficultyaras lowrendah, ChapterBab 3, standard 3.2

TextbookBuku teks p.ms. 90

7

QuestionSoalan 7

Seorang penderma menderma 400 mL darah di sebuah hospital. Kira-kira berapakah isi padu plasma dalam darah yang didermakan itu?A donor gives 400 mL of blood at a hospital. About what volume of the donated blood is plasma?

• A220 mL
• B180 mL
• C360 mL
• D4 mL

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A

Plasma is about 55% of blood: 55 ÷ 100 × 400 = 220 mL. 180 mL is the red blood cells (45%), 360 mL is 90% (the water content of plasma) and 4 mL is less than 1% (white blood cells and platelets).

For the teacherUntuk guru: ApplyingMengaplikasi, mediumsederhana difficultyaras mediumsederhana, ChapterBab 3, standard 3.3

TextbookBuku teks p.ms. 97

8

QuestionSoalan 8

Galena ialah bijih plumbum. Apakah unsur-unsur yang bergabung dalam plumbum(II) sulfida, nama saintifik bagi galena?Galena is an ore of lead. What are the elements combined in lead(II) sulphide, the scientific name of galena?

• APlumbum dan oksigenLead and oxygen
• BFerum dan sulfurIron and sulphur
• CPlumbum dan sulfurLead and sulphur
• DKalsium, karbon dan oksigenCalcium, carbon and oxygen

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C

Galena (plumbum(II) sulphide) is made of lead and sulphur. Lead and oxygen would be lead oxide, iron and sulphur make pyrite, and calcium, carbon and oxygen make calcite (calcium carbonate).

For the teacherUntuk guru: RememberingMengingat, lowrendah difficultyaras lowrendah, ChapterBab 4, standard 4.1

TextbookBuku teks p.ms. 125

9

QuestionSoalan 9

Pasangan logam yang manakah kedua-duanya boleh diekstrak daripada oksidanya dengan memanaskan oksida itu bersama karbon?Which pair of metals can both be extracted from their oxides by heating the oxides with carbon?

• ANatrium dan zinkSodium and zinc
• BAluminium dan ferumAluminium and iron
• CFerum dan plumbumIron and lead
• DMagnesium dan stanumMagnesium and tin

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C

Carbon can remove oxygen only from the oxides of metals below it in the reactivity series: zinc, iron, tin and lead. Sodium, aluminium and magnesium are above carbon and are extracted by electrolysis of the molten compound.

For the teacherUntuk guru: ApplyingMengaplikasi, mediumsederhana difficultyaras mediumsederhana, ChapterBab 4, standard 4.3

TextbookBuku teks p.ms. 137

10

QuestionSoalan 10

Antara pasangan tindak balas dan perubahan haba yang berikut, yang manakah betul?Which of the following pairs of reaction and heat change is correct?

• APeneutralan asid dengan alkali: haba dibebaskanNeutralisation of an acid with an alkali: heat is released
• BFotosintesis: haba dibebaskanPhotosynthesis: heat is released
• CPemanasan kalsium karbonat: haba dibebaskanHeating calcium carbonate: heat is released
• DPelarutan ammonium klorida dalam air: haba dibebaskanDissolving ammonium chloride in water: heat is released

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A

Neutralisation is exothermic: heat is released. Photosynthesis, the thermal decomposition of calcium carbonate and the dissolving of ammonium chloride all absorb heat (endothermic).

For the teacherUntuk guru: UnderstandingMemahami, lowrendah difficultyaras lowrendah, ChapterBab 5, standard 5.1.4

TextbookBuku teks p.ms. 154

11

QuestionSoalan 11

Sebuah pek panas segera mengandungi kalsium klorida dan satu beg kecil air. Pernyataan manakah yang betul tentang pek itu?An instant hot pack contains calcium chloride and a small bag of water. Which statement about the pack is correct?

• AIa melegakan bengkak kerana haba diserap daripada bahagian yang bengkak.It relieves swelling because heat is absorbed from the swollen part.
• BIa melegakan kejang otot kerana haba dibebaskan dan lumen kapilari darah menjadi lebih luas supaya darah mengalir lebih laju.It relieves muscle cramp because heat is released and the lumen of the blood capillaries widens so that the blood flows faster.
• CIa menghentikan pendarahan kerana haba dibebaskan dan lumen kapilari darah menjadi sempit.It stops bleeding because heat is released and the lumen of the blood capillaries narrows.
• DIa melegakan kejang otot kerana pelarutan kalsium klorida menyerap haba.It relieves muscle cramp because the dissolving of calcium chloride absorbs heat.

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B

Dissolving calcium chloride in water is exothermic. The heat released relieves muscle cramp and widens the lumen of the blood capillaries so that blood flows faster. Absorbing heat (A, D) and narrowing the capillaries (C) belong to a cold pack.

For the teacherUntuk guru: UnderstandingMemahami, mediumsederhana difficultyaras mediumsederhana, ChapterBab 5, standard 5.1.5

TextbookBuku teks p.ms. 153

12

QuestionSoalan 12

Rajah 1 menunjukkan skrin osiloskop sinar katod (O.S.K.) apabila sebuah bekalan arus ulang-alik disambungkan kepada input-Y dengan gandaan-Y 5 V per bahagian. Apakah voltan maksimum bekalan itu?Diagram 1 shows the screen of a cathode ray oscilloscope (C.R.O.) when an alternating current supply is connected to the Y-input with the Y-gain at 5 V per division. What is the maximum voltage of the supply?

• A0.6 V
• B8 V
• C30 V
• D15 V

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D

Voltage = displacement × Y-gain. The crest is 3 divisions above the zero line, so the maximum voltage = 3 × 5 = 15 V. 30 V uses the distance from crest to trough (6 divisions), 8 V adds 3 and 5, and 0.6 V divides instead of multiplying.

For the teacherUntuk guru: ApplyingMengaplikasi, mediumsederhana difficultyaras mediumsederhana, ChapterBab 6, standard 6.1.3

TextbookBuku teks p.ms. 172

13

QuestionSoalan 13

Sebuah seterika elektrik dilabelkan 1 000 W, 240 V. Fius manakah yang paling sesuai untuk palam seterika itu? Fius yang dipilih ialah fius bernilai paling kecil yang tidak melebur semasa seterika digunakan secara biasa.An electric iron is labelled 1 000 W, 240 V. Which fuse is the most suitable for the plug of the iron? The fuse chosen is the one of the lowest value that does not melt when the iron is used normally.

• A3 A
• B13 A
• C5 A
• D30 A

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C

I = P ÷ V = 1 000 ÷ 240 = 4.2 A. The fuse must be slightly higher than the normal current, and the lowest such value is 5 A. A 3 A fuse would melt at once, while 13 A and 30 A are too high to protect the iron properly.

For the teacherUntuk guru: ApplyingMengaplikasi, mediumsederhana difficultyaras mediumsederhana, ChapterBab 6, standard 6.3.2

TextbookBuku teks p.ms. 191

14

QuestionSoalan 14

Sebuah lampu 60 W dipasang selama 5 jam setiap hari di sebuah wad hospital. Kadar elektrik ialah 30 sen seunit. Berapakah kos untuk menggunakan lampu itu selama 10 hari?A 60 W lamp is switched on for 5 hours every day in a hospital ward. The rate of electricity is 30 sen per unit. What is the cost of using the lamp for 10 days?

• A90 sen
• B9 sen
• C900 sen
• D300 sen

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A

60 W = 0.06 kW. Energy = 0.06 × 5 × 10 = 3 kWh. Cost = 3 × 30 = 90 sen. 900 sen forgets to change watts to kilowatts, 9 sen uses one day only and 300 sen is 3 units × 100.

For the teacherUntuk guru: ApplyingMengaplikasi, lowrendah difficultyaras lowrendah, ChapterBab 6, standard 6.4.4

TextbookBuku teks p.ms. 200

15

QuestionSoalan 15

Sebuah troli berjisim 6 kg bergerak pada laju 2 m s⁻¹ dan mempunyai tenaga kinetik 12 J. Berapakah tenaga kinetik troli itu apabila lajunya menjadi 6 m s⁻¹?A trolley of mass 6 kg moves at a speed of 2 m s⁻¹ and has 12 J of kinetic energy. What is the kinetic energy of the trolley when its speed becomes 6 m s⁻¹?

• A36 J
• B72 J
• C54 J
• D108 J

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D

Ek = ½mv² = ½ × 6 × 6² = 108 J. The speed is tripled, so the kinetic energy becomes 3² = 9 times larger: 9 × 12 = 108 J. 36 J multiplies by 3 only.

For the teacherUntuk guru: ApplyingMengaplikasi, hightinggi difficultyaras hightinggi, ChapterBab 7, standard 7.2

TextbookBuku teks p.ms. 220

16

QuestionSoalan 16

Sebuah motor lif mengangkat beban berjisim 800 kg setinggi 12 m dalam masa 0.4 minit. Berapakah kuasa motor itu?A lift motor raises a load of mass 800 kg through a height of 12 m in 0.4 minute. What is the power of the motor?

• A96 000 W
• B4 000 W
• C400 W
• D240 000 W

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B

Work = mgh = 800 × 10 × 12 = 96 000 J. Time = 0.4 × 60 = 24 s. Power = 96 000 ÷ 24 = 4 000 W. 96 000 W is the work in joules, and 240 000 W uses 0.4 s instead of 24 s.

For the teacherUntuk guru: ApplyingMengaplikasi, mediumsederhana difficultyaras mediumsederhana, ChapterBab 7, standard 7.1.2

TextbookBuku teks p.ms. 213

17

QuestionSoalan 17

Sebuah sampel radioaktif berjisim 640 g mempunyai separuh hayat 12 hari. Berapakah jisim sampel yang belum mereput selepas 60 hari?A radioactive sample of mass 640 g has a half-life of 12 days. What is the mass of the sample that has not decayed after 60 days?

• A20 g
• B40 g
• C10 g
• D128 g

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A

60 ÷ 12 = 5 half-lives. 640 → 320 → 160 → 80 → 40 → 20, so 20 g remains. 40 g counts only 4 half-lives, 10 g counts 6, and 128 g divides by 5.

For the teacherUntuk guru: ApplyingMengaplikasi, mediumsederhana difficultyaras mediumsederhana, ChapterBab 8, standard 8.1.2

TextbookBuku teks p.ms. 235

18

QuestionSoalan 18

Antara berikut, yang manakah sumber buatan manusia bagi sinaran mengion?Which of the following is a man-made source of ionising radiation?

• ASinar kosmikCosmic rays
• BSinaran latar belakangBackground radiation
• CUjian senjata nuklearNuclear weapon tests
• DGelombang radioRadio waves

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C

Nuclear tests, nuclear accidents and radioisotopes used in medicine are man-made sources. Cosmic rays and background radiation are natural sources, and radio waves are non-ionising.

For the teacherUntuk guru: RememberingMengingat, lowrendah difficultyaras lowrendah, ChapterBab 8, standard 8.3.2

TextbookBuku teks p.ms. 242

19

QuestionSoalan 19

Bilangan tompok Matahari mencapai maksimum pada tahun 2014. Dalam tahun manakah maksimum yang berikutnya dijangka berlaku?The number of sunspots reached a maximum in 2014. In which year is the next maximum expected?

• A2016
• B2020
• C2036
• D2025

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D

The solar cycle, the rise and fall in sunspot activity, lasts 11 years, so the next maximum is expected in 2014 + 11 = 2025. 2036 would be two cycles later.

For the teacherUntuk guru: ApplyingMengaplikasi, lowrendah difficultyaras lowrendah, ChapterBab 9, standard 9.1.1

TextbookBuku teks p.ms. 259

20

QuestionSoalan 20

Siapakah angkasawan pertama Malaysia yang menjalankan eksperimen di Stesen Angkasa Antarabangsa (ISS) pada tahun 2007?Who was the first Malaysian astronaut to carry out experiments on the International Space Station (ISS) in 2007?

• ANeil Armstrong
• BDato' Dr Sheikh Muszaphar Shukor
• CYuri Gagarin
• DGalileo Galilei

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B

Dato' Dr Sheikh Muszaphar Shukor was Malaysia's first astronaut and carried out experiments on the ISS from 10 to 21 October 2007. Neil Armstrong was the first person on the Moon (1969), Yuri Gagarin the first person to orbit Earth (1961) and Galileo used the first telescope in astronomy (1609).

For the teacherUntuk guru: RememberingMengingat, lowrendah difficultyaras lowrendah, ChapterBab 10, standard 10.2

TextbookBuku teks p.ms. 269

26

QuestionSoalan 26

Seorang juruaudiologi di sebuah hospital menguji pendengaran empat pesakit, P, Q, R dan S. Setiap pesakit mendengar bunyi yang frekuensinya dinaikkan secara beransur-ansur melalui fon kepala. Jadual 1 menunjukkan frekuensi tertinggi yang dapat didengar oleh setiap pesakit.

Jadual 1 / Table 1

Pesakit / Patient	Umur / Age (tahun / years)	Frekuensi tertinggi / Highest frequency (Hz)
P	12	19 000
Q	35	16 000
R	58	11 000
S	74	7 000

An audiologist at a hospital tests the hearing of four patients, P, Q, R and S. Each patient listens through headphones to a sound whose frequency is raised slowly. Table 1 shows the highest frequency each patient can hear.

[2 marksmarkah] (a)Nyatakan hubungan antara umur pesakit dengan frekuensi tertinggi yang dapat didengar, dan beri satu sebab bagi hubungan itu.State the relationship between the age of the patient and the highest frequency that can be heard, and give one reason for the relationship.

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• As age increases, the highest frequency that can be heard decreases [1]1
• The eardrum becomes less elastic with age [1]1

Tick each point you got.Tandakan setiap isi yang betul.

[1 markmarkah] (b)Nyatakan julat frekuensi pendengaran manusia yang normal.State the normal range of frequencies of human hearing.

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• 20 Hz to 20 000 Hz1

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[2 marksmarkah] (c)Lengkapkan carta alir bagi mekanisme pendengaran: Cuping telinga → saluran telinga → ____ → osikel → tingkap bujur → ____ → saraf auditori → otak.Complete the flow chart of the mechanism of hearing: Earlobe → ear canal → ____ → ossicles → oval window → ____ → auditory nerve → brain.

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• Eardrum [1]1
• Cochlea [1]1

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[2 marksmarkah] (d)Pesakit T mempunyai koklea yang rosak tetapi saraf auditori yang baik. Pesakit U mempunyai saraf auditori yang rosak. Pesakit manakah boleh dibantu dengan implan koklea? Terangkan.Patient T has a damaged cochlea but a healthy auditory nerve. Patient U has a damaged auditory nerve. Which patient can be helped with a cochlear implant? Explain.

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• Patient T [1]1
• In patient U the impulses cannot reach the brain, and a damaged auditory nerve cannot be corrected by an implant, medicine or surgery [1]1

Tick each point you got.Tandakan setiap isi yang betul.

[1 markmarkah] (e)Namakan bahagian telinga yang mengesan kedudukan kepala dan membantu mengimbangi badan.Name the part of the ear that detects the position of the head and helps to balance the body.

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• Semicircular canals1

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For the teacherUntuk guru: UnderstandingMemahami, lowrendah difficultyaras lowrendah, ChapterBab 1, standard 1.2.4

TextbookBuku teks p.ms. 26

27

QuestionSoalan 27

Sebuah syarikat perlombongan di Malaysia mengekstrak logam daripada tiga bijih. Jadual 2 menunjukkan nama saintifik bagi bijih itu dan kedudukan logamnya berbanding karbon dalam siri kereaktifan.

Jadual 2 / Table 2

Bijih / Ore	Nama saintifik / Scientific name	Kedudukan logam / Position of the metal
Kasiterit / Cassiterite	Stanum(IV) oksida / Tin(IV) oxide	Di bawah karbon / Below carbon
Hematit / Hematite	Ferum(III) oksida / Iron(III) oxide	Di bawah karbon / Below carbon
Bauksit / Bauxite	Aluminium oksida / Aluminium oxide	Di atas karbon / Above carbon

A mining company in Malaysia extracts metals from three ores. Table 2 shows the scientific name of each ore and the position of its metal compared with carbon in the reactivity series.

[1 markmarkah] (a)Namakan unsur-unsur yang bergabung dalam hematit.Name the elements combined in hematite.

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• Iron and oxygen1

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[1 markmarkah] (b)Tulis persamaan perkataan bagi tindak balas apabila stanum(IV) oksida dipanaskan dengan karbon.Write the word equation for the reaction when tin(IV) oxide is heated with carbon.

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• Tin(IV) oxide + carbon → tin + carbon dioxide1

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[2 marksmarkah] (c)Nyatakan kaedah yang digunakan untuk mengekstrak aluminium dan ferum daripada oksidanya.State the method used to extract aluminium and iron from their oxides.

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• Aluminium: electrolysis of the molten aluminium oxide [1]1
• Iron: heating the iron(III) oxide with carbon (reduction) [1]1

Tick each point you got.Tandakan setiap isi yang betul.

[2 marksmarkah] (d)Terangkan mengapa aluminium tidak boleh diekstrak daripada aluminium oksida dengan memanaskannya bersama karbon.Explain why aluminium cannot be extracted from aluminium oxide by heating it with carbon.

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• Carbon is less reactive than aluminium [1]1
• So carbon cannot remove the oxygen from aluminium oxide [1]1

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[2 marksmarkah] (e)Emas dijumpai sebagai unsur dalam kerak Bumi dan tidak perlu diekstrak daripada sebatian. Terangkan mengapa.Gold is found as an element in the Earth's crust and does not need to be extracted from a compound. Explain why.

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• Gold is very unreactive (it is at the bottom of the reactivity series) [1]1
• So it does not react with oxygen or other substances in the crust to form compounds [1]1

Tick each point you got.Tandakan setiap isi yang betul.

For the teacherUntuk guru: UnderstandingMemahami, lowrendah difficultyaras lowrendah, ChapterBab 4, standard 4.3

TextbookBuku teks p.ms. 137

28

QuestionSoalan 28

Siti dan Daniel mengkaji bagaimana bilangan lilitan pada gegelung mempengaruhi arus teraruh. Mereka menolak kutub utara sebuah magnet bar ke dalam gegelung yang disambungkan kepada galvanometer pusat sifar, pada laju yang sama setiap kali, dan merekod pesongan maksimum penunjuk. Rajah 2 menunjukkan radas dan Jadual 3 menunjukkan keputusan.

Jadual 3 / Table 3

Bilangan lilitan / Number of turns	20	40	60	80
Pesongan penunjuk / Deflection of pointer (bahagian / divisions)	2	4	6	8

Siti and Daniel investigate how the number of turns in a coil affects the induced current. They push the north pole of a bar magnet into a coil connected to a centre-zero galvanometer, at the same speed each time, and record the maximum deflection of the pointer. Diagram 2 shows the apparatus and Table 3 shows the results.

[3 marksmarkah] (a)Nyatakan pemboleh ubah dimanipulasikan, pemboleh ubah bergerak balas dan satu pemboleh ubah dimalarkan dalam eksperimen ini.State the manipulated variable, the responding variable and one fixed variable in this experiment.

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• Manipulated: number of turns of the coil [1]1
• Responding: deflection of the galvanometer pointer (size of the induced current) [1]1
• Fixed (any one): speed at which the magnet is pushed / the same magnet (strength and pole) / the same coil material and size [1]1

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[1 markmarkah] (b)Nyatakan definisi secara operasi bagi arus teraruh yang lebih besar dalam eksperimen ini.State the operational definition of a larger induced current in this experiment.

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• A larger induced current is when the pointer of the galvanometer deflects through more divisions1

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[2 marksmarkah] (c)Nyatakan hubungan antara bilangan lilitan dengan arus teraruh. Ramalkan pesongan penunjuk jika gegelung itu mempunyai 120 lilitan.State the relationship between the number of turns and the induced current. Predict the deflection of the pointer if the coil has 120 turns.

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• As the number of turns increases, the induced current increases (it is directly proportional: double the turns, double the deflection) [1]1
• 12 divisions [1]1

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[2 marksmarkah] (d)Sebuah penjana di sebuah stesen hidroelektrik di empangan digerakkan oleh turbin. Nyatakan perubahan tenaga dalam stesen itu.A generator at a hydroelectric power station at a dam is turned by a turbine. State the energy changes in the station.

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• Gravitational potential energy of the water in the dam → kinetic energy of the falling water (turns the turbine) [1]1
• → electrical energy (in the generator) [1]1

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[2 marksmarkah] (e)Arus ulang-alik daripada penjana itu dihantar melalui Grid Nasional. Namakan bahagian yang menaikkan voltan sebelum penghantaran dan nyatakan jenis arus yang dihantar.The alternating current from the generator is sent through the National Grid. Name the part that increases the voltage before transmission and state the type of current that is transmitted.

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• Step-up transformer station [1]1
• Alternating current (a.c.) [1]1

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For the teacherUntuk guru: AnalysingMenganalisis, mediumsederhana difficultyaras mediumsederhana, ChapterBab 6, standard 6.1

TextbookBuku teks p.ms. 164

29

QuestionSoalan 29

Sebuah hospital menggunakan natrium-24 untuk mengesan sekatan dalam salur darah pesakit. Aktiviti sebuah sampel natrium-24 direkodkan dalam Jadual 4.

Jadual 4 / Table 4

Masa / Time (jam / hours)	0	15	30	45	60
Aktiviti / Activity (Bq)	1 280	640	320	160	80

A hospital uses sodium-24 to locate blockages in the blood vessels of a patient. The activity of a sample of sodium-24 is recorded in Table 4.

[1 markmarkah] (a)Berdasarkan Jadual 4, nyatakan separuh hayat natrium-24.Based on Table 4, state the half-life of sodium-24.

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• 15 hours (activity halves from 1 280 Bq to 640 Bq in 15 h)1

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[2 marksmarkah] (b)Berapakah aktiviti sampel itu selepas 90 jam?What is the activity of the sample after 90 hours?

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• 90 ÷ 15 = 6 half-lives [1]1
• 1 280 → 640 → 320 → 160 → 80 → 40 → 20: 20 Bq [1]1

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[2 marksmarkah] (c)Berapa lamakah masa diambil untuk aktiviti sampel itu jatuh kepada 5 Bq?How long does it take for the activity of the sample to fall to 5 Bq?

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• 1 280 → 640 → 320 → 160 → 80 → 40 → 20 → 10 → 5 is 8 half-lives [1]1
• 8 × 15 = 120 hours [1]1

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[2 marksmarkah] (d)Aiman berkata, "Jika sampel itu dipanaskan hingga 500 °C, separuh hayatnya akan menjadi lebih pendek." Nilaikan kenyataan Aiman.Aiman says, "If the sample is heated to 500 °C, its half-life will become shorter." Evaluate Aiman's statement.

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• The statement is wrong [1]1
• Radioactive decay is random and spontaneous: it is not affected by heat, pressure or chemicals, so the half-life stays 15 hours [1]1

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[3 marksmarkah] (e)Sebuah mangkuk kayu yang dijumpai di tapak arkeologi mempunyai aktiviti karbon-14 sebanyak 1/16 daripada aktiviti kayu yang baru ditebang. Separuh hayat karbon-14 ialah 5 700 tahun. (i) Hitung umur mangkuk itu. (ii) Nyatakan jenis sinaran yang dipancarkan oleh karbon-14.A wooden bowl found at an archaeological site has a carbon-14 activity that is 1/16 of the activity of freshly cut wood. The half-life of carbon-14 is 5 700 years. (i) Calculate the age of the bowl. (ii) State the type of radiation emitted by carbon-14.

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• 1 → 1/2 → 1/4 → 1/8 → 1/16 is 4 half-lives [1]1
• Age = 4 × 5 700 = 22 800 years [1]1
• Beta particles [1]1

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For the teacherUntuk guru: ApplyingMengaplikasi, lowrendah difficultyaras lowrendah, ChapterBab 8, standard 8.1.2

TextbookBuku teks p.ms. 236

30

QuestionSoalan 30

Seorang jururawat di sebuah hospital ingin membuat pek sejuk segera untuk merawat hidung yang berdarah. Dia melarutkan ammonium nitrat dalam 50 mL air pada suhu 30 °C di dalam cawan polistirena dan merekod suhu campuran setiap minit. Rajah 3 menunjukkan graf suhu melawan masa bagi 6 g ammonium nitrat. Jadual 5 menunjukkan penurunan suhu bagi jisim ammonium nitrat yang berlainan dalam 50 mL air.

Jadual 5 / Table 5

Jisim ammonium nitrat / Mass of ammonium nitrate (g)	2	4	6	8
Penurunan suhu / Fall in temperature (°C)	3	6	9	12

A nurse at a hospital wants to make an instant cold pack to treat a nosebleed. She dissolves ammonium nitrate in 50 mL of water at 30 °C in a polystyrene cup and records the temperature of the mixture every minute. Diagram 3 shows the graph of temperature against time for 6 g of ammonium nitrate. Table 5 shows the fall in temperature for different masses of ammonium nitrate in 50 mL of water.

[1 markmarkah] (a)Nyatakan jenis tindak balas itu dan beri satu sebab berdasarkan Rajah 3.State the type of reaction and give one reason based on Diagram 3.

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• Endothermic, because the temperature of the mixture falls (heat is absorbed from the surroundings)1

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[2 marksmarkah] (b)Berdasarkan Rajah 3, nyatakan suhu minimum dan pada minit ke berapa suhu itu dicapai.Based on Diagram 3, state the minimum temperature and the minute at which it is reached.

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• 21 °C [1]1
• At the 4th minute [1]1

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[1 markmarkah] (c)Hitung penurunan suhu campuran itu.Calculate the fall in temperature of the mixture.

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• 30 − 21 = 9 °C1

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[2 marksmarkah] (d)Berdasarkan Jadual 5, nyatakan pemboleh ubah dimanipulasikan dan pemboleh ubah bergerak balas.Based on Table 5, state the manipulated variable and the responding variable.

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• Manipulated: mass of ammonium nitrate [1]1
• Responding: fall in temperature [1]1

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[1 markmarkah] (e)Nyatakan hubungan antara jisim ammonium nitrat dengan penurunan suhu.State the relationship between the mass of ammonium nitrate and the fall in temperature.

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• As the mass of ammonium nitrate increases, the fall in temperature increases (directly proportional)1

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[2 marksmarkah] (f)Jururawat itu memerlukan pek yang suhunya turun daripada 30 °C kepada 12 °C dalam 50 mL air. Hitung jisim ammonium nitrat yang diperlukan.The nurse needs a pack whose temperature falls from 30 °C to 12 °C in 50 mL of water. Calculate the mass of ammonium nitrate needed.

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• Fall needed = 30 − 12 = 18 °C; each 2 g gives a fall of 3 °C (1.5 °C per gram) [1]1
• Mass = 18 ÷ 1.5 = 12 g [1]1

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[3 marksmarkah] (g)Aiman mengulangi eksperimen itu dengan 8 g ammonium nitrat tetapi menggunakan 100 mL air, dan suhu turun sebanyak 6 °C sahaja. Dia membuat kesimpulan bahawa "lebih banyak ammonium nitrat memberi penurunan suhu yang lebih kecil". Nilaikan kesimpulan Aiman dan cadangkan satu pembetulan.Aiman repeats the experiment with 8 g of ammonium nitrate but uses 100 mL of water, and the temperature falls by only 6 °C. He concludes that "more ammonium nitrate gives a smaller fall in temperature". Evaluate Aiman's conclusion and suggest one correction.

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• The conclusion is not valid / wrong [1]1
• He changed the volume of water (a fixed variable) as well as the mass, so it is not a fair test and the results cannot be compared [1]1
• Correction: use 50 mL of water again (keep the volume of water the same) [1]1

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For the teacherUntuk guru: EvaluatingMenilai, mediumsederhana difficultyaras mediumsederhana, ChapterBab 5, standard 5.1.5

TextbookBuku teks p.ms. 153

31

QuestionSoalan 31

Seorang juruteknik makmal di sebuah hospital mengenal pasti kumpulan darah empat pesakit, P, Q, R dan S, dengan mencampurkan plasma setiap pesakit dengan sel darah merah daripada kumpulan A, B, AB dan O yang diketahui. Jadual 6 menunjukkan sama ada sel darah merah itu menggumpal (✓) atau tidak (✗).

Jadual 6 / Table 6

Plasma pesakit / Patient's plasma	Sel darah merah A / Red cells A	Sel darah merah B / Red cells B	Sel darah merah AB / Red cells AB	Sel darah merah O / Red cells O
P	✗	✓	✓	✗
Q	✓	✓	✓	✗
R	✗	✗	✗	✗
S	✓	✗	✓	✗

Rajah 4 menunjukkan aliran darah dalam sistem peredaran darah manusia.A laboratory technician at a hospital identifies the blood groups of four patients, P, Q, R and S, by mixing the plasma of each patient with red blood cells of known groups A, B, AB and O. Table 6 shows whether the red blood cells clump (✓) or not (✗). Diagram 4 shows the flow of blood in the human circulatory system.

[2 marksmarkah] (a)Nyatakan kumpulan darah pesakit Q dan antibodi dalam plasmanya.State the blood group of patient Q and the antibodies in its plasma.

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• Group O [1]1
• Anti-A and Anti-B [1]1

Plasma Q clumps red cells A, B and AB but not O, so it has both Anti-A and Anti-B, which only group O has.

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[2 marksmarkah] (b)Nyatakan kumpulan darah pesakit R dan terangkan mengapa R boleh menerima darah daripada semua kumpulan.State the blood group of patient R and explain why R can receive blood from all groups.

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• Group AB [1]1
• Plasma of R has no antibodies, so nothing attacks the antigens of the donor's red blood cells [1]1

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[2 marksmarkah] (c)Pesakit S (kumpulan B) memerlukan pemindahan darah. Antara pesakit P, Q dan R, siapakah yang darahnya sesuai diberikan kepada S? Beri satu sebab.Patient S (group B) needs a blood transfusion. Among patients P, Q and R, whose blood is suitable to be given to S? Give one reason.

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• Q (group O) [1]1
• Red blood cells of group O have no antigens, so the Anti-A in the plasma of S has nothing to attack [1]1

P is group A (antigen A) and R is group AB (antigens A and B); the Anti-A in S would clump both.

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[2 marksmarkah] (d)Berdasarkan Rajah 4, namakan salur darah X dan salur darah Y.Based on Diagram 4, name blood vessel X and blood vessel Y.

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• X: pulmonary artery [1]1
• Y: vena cava [1]1

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[1 markmarkah] (e)Mengapakah peredaran darah manusia dipanggil peredaran ganda dua?Why is the circulation of blood in humans called a double circulation?

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• Blood passes through the heart twice in one complete circuit of the body (once in the pulmonary circulation and once in the systemic circulation)1

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[3 marksmarkah] (f)Bank darah hospital mempunyai 3 unit darah kumpulan O dan 4 unit darah kumpulan B. Pesakit Q dan pesakit S masing-masing memerlukan 3 unit darah. Cadangkan bagaimana darah itu harus diberikan dan justifikasikan cadangan anda.The blood bank of the hospital has 3 units of group O blood and 4 units of group B blood. Patient Q and patient S each need 3 units of blood. Suggest how the blood should be given and justify your suggestion.

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• Give all 3 units of group O to patient Q [1]1
• Q has Anti-A and Anti-B, so group O is the only group Q can receive safely [1]1
• Give 3 units of group B to patient S, because it is the same group and keeps group O for Q (S could also take group O, but then Q would have no safe blood) [1]1

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For the teacherUntuk guru: EvaluatingMenilai, hightinggi difficultyaras hightinggi, ChapterBab 3, standard 3.3

TextbookBuku teks p.ms. 98

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