Public Assessment of the HKDSE Physics Examination1.PublicAssessmentThe public assessment of the Hong Kong Diploma of Secondary Education (HKDSE) Physics Exam consists of a public examination component and a school-based assessment component.

A. PublicExaminationcomponentIn Physics, the mark of the public examination component contributes 80% of the final subject mark.

Paper Section Question types Weighing Duration Curriculum

Paper 1Section A Multiple-choice Questions 21%

2 hours 30 minutes Compulsory Part

Section B Short Questions and Structured / Essay-type Questions 39%

Paper 2 – Multiple-choice Questions and Structured Questions 20% 1 hour Elective Part

(2 out of 4)

B. School-basedAssessmentcomponentIn Physics, students are assessed by their teachers on their performance of a wide range of skills involved in practical and non-practical related tasks throughout S.5 and S.6. The mark of the school-based assessment component contributes 20% of the final subject mark.

Year of examination Assessment types Weighing2012 and 2013 Practical related component 20%

Starting from 2014Practical related component 18%

Non-practical related component 2%

2.Standards-referencedReportingThe HKDSE makes use of standards-referenced reporting, which means candidates’ levels of performance will be reported with reference to a set of standards as defined by cut scores on the variable or scale for a given subject. The following diagram represents the set of standards for a given subject:

Cut scores

U 1 2 3 4 5

Variable/scale

Within the context of the HKDSE there will be five cut scores, which will be used to distinguish five levels of performance (1–5), with 5 being the highest. The Level 5 candidates with the best performance will have their results annotated with the symbols ∗∗ and the next top group with the symbol ∗. A performance below the threshold cut score for Level 1 will be labelled as ‘Unclassified’ (U).

– II –

Exam StrategiesA. TimeAllocation

Paper1(CompulsoryPart)——2hours30minutes

Section Suggested Time Allocation Approximate Time per Question

A 60 minutes 1.5 minutes

B 90 minutes 5 – 10 minutes

– Allow 5 minutes for final checking.

Paper2(ElectivePart)——1hour

Time Allowed Approximate Time per Question

60 minutes (answering 2 out of 4 questions) 25 – 30 minutes

– Allow 5 minutes for final checking.

B. AnsweringSkills• Pay attention to the units in calculation, especially in the conversion between

– kg, g and µg,– km, m, cm, mm, µm and nm,– year, day, h, min, s, ms and µs.

• Take g = 9.81 m s-2 in all questions. Look up the numerical values of the constants and formulae that you need at the back cover of the exam paper.

Paper1A Multiple-choiceQuestions

• Make your draft next to each question so that the draft can be referenced during final checking.• Mark only ONE answer for each question.• The statements in the options may be misleading. DO NOT spend too much time in reading the

options.• DO NOT leave any questions unanswered even if you do not know the answer.

Paper1B ShortQuestionsandStructured/Essay-typeQuestions

• Skip the questions that you do not have confidence on. Go back to those questions after you have finished the others.

• The units of physical quantities must be written. Unless otherwise specified, numerical answers should be either exact or correct to 3 significant figures.

• In answering questions involving calculations, show your steps rather than just writing down the answers. In case you do not get the correct answer, you can get marks for the correct methods used.

• In answering questions involving drawing:– Always use a pencil.– Draw diagrams and graphs with tools like rulers.– Choose an appropriate scale.– Name the apparatus used. / Name all forces. / Label the axes.

– III –

Sample Paper AnalysisPaper1(CompulsoryPart)

Paper 1A consists of 36 MC questions. Paper 1B consists of 14 questions. The full mark of the paper is 84.

Distribution of Exam Questions:

Paper 1A Paper 1B

I. Heat and Gases 1 – 4 1, 9

II. Force and Motion 5 – 14 2, 3, 11

III. Wave Motion 15 – 23 4, 5, 6, 10

IV. Electricity and Magnetism 24 – 33 7, 8, 12, 13

V. Radioactivity and Nuclear Energy 34 – 36 14

About 70% of the questions are set at the former HKCE Examination level. The rest (30% of the questions) are set at the former HKAL Examination level.

Paper2(ElectivePart)

There are 4 sections in Paper 2, each consists of 8 MC questions and a structured question.

Distribution of MC Questions:

Paper 2

VI. Astronomy and Space Science 1 – 3 : The universe as seen in different scales4 : Astronomy through history5 – 6 : Orbital motions under gravity7 – 8 : Stars and the universe

VII. Atomic World 1 : Rutherford’s atomic model2, 5 – 6 : Photoelectric effect3 – 4 : Bohr’s atomic model of hydrogen7 : Particles or waves8 : Probing into nano scale

VIII. Energy and Use of Energy 1 – 2 : Electricity at home4 – 5 : Energy efficiency in building and transportation3, 6 – 8 : Renewable and non-renewable energy sources

IX. Medical Physics 1 : Making sense of the eye and the ear2 – 4 : Medical imaging using non-ionizing radiation5 – 8 : Medical imaging using ionizing radiation

– V –

Common Mistake AnalysisI. HeatandGases

1. Beawareofthemeaningoftemperaturedifference.Example:200 g of water at 80°C is mixed with 800 g of water at 20°C. Assuming that there is no heat lost to the surroundings, what is the final temperature of the mixture?Ans:Let T be the final temperature of the mixture, where 20°C < T < 80°C.

0.2 × c × (80 – T) = 0.8 × c × (T – 20) 16 – 0.2T = 0.8T – 16 T = 32°C

2. Inquestionsinvolvingthegaslaws,temperaturemustbeexpressedintheKelvinscale.Example:The volume of a balloon is 2300 cm3 at 25°C. If it is cooled down to 4°C, what will be the volume of the balloon?Ans:Charles’ law:

V

T

V

T

V

V

1

1

2

2

2

23

230025 273 4 273

2140

=

+=

+= cm

II. ForceandMotion

3. Inquestionsinvolvinghorizontalcircularmotion,theresultantforceishorizontal.Example:A small ball of mass 40 g is hung by an inextensible light string of 24 cm long. The ball is then set to perform a horizontal uniform circular motion. If the ball completes 2.5 revolutions per second, what will be the tension in the string?Ans:

T mr

m L

T mL

sin

( sin )

. ( . )( . )

θ ω

θ ω

ω

=

=

=

= ×

2

2

2

20 04 0 24 2 2 5π== 2 37. N

It is incorrect to write (T – 80).

Add 273 to each Celsius temperature.

Resolve the tension in the string and relate the horizontal component with centripetal force.

– VI –

©  香港教育圖書公司  保留版權Hong Kong Educational Publishing Co.All Rights Reserved 2011

GENERAL INSTRUCTIONS

1. There areTWO sections,A andB, in this Paper. SectionA consists ofmultiple-choice questions in thisquestion book, while Section B contains conventional questions printed separately in Question-AnswerBookB.You are advised tofinishSectionA in about 60minutes.

2. Answers to SectionA should bemarked on theMultiple-choiceAnswer Sheetwhile answers to SectionB should be written in the spaces provided in Question-Answer Book B. The Answer Sheet for Section A and the Question-Answer Book for Section B must be handed in separately at the end of the examination.

SECTION A (MULTIPLE-CHOICE QUESTIONS)

INSTRUCTIONS FOR SECTION A

1. Read the instructions on the Answer Sheet carefully. After the announcement of the start of theexamination, you should stick abarcode label and insert the information required in the spacesprovided.No extra timewill begiven for sticking thebarcode label after the ‘Time is up’ announcement.

2. When told to open this book, you should check that all the questions are there. Look for the wordsʻEND OF SECTION Aʼ after the last question.

3. All questions carry equalmarks.

4. ANSWER ALL QUESTIONS. You are advised to use an HB pencil to mark all the answers on theAnswerSheet, so thatwrongmarks canbe completely erasedwith a clean rubber.

5. You should mark only ONE answer for each question. If you mark more than one answer, you willreceiveNO MARKS for that question.

6. Nomarkswill bededucted forwrong answers.

MOCK7PAPER1A-1

Time allowed: 2 hours 30 minutesThis paper must be answered in English.

PHYSICS MOCK EXAM 7PAPER 1

HONG KONG EDUCATIONAL PUBLISHING CO.HONG KONG DIPLOMA OF SECONDARY EDUCATION EXAMINATION

Not to be taken away before the end of the examination session

MC

HKDSEPHYPAPER 1

–229–

–230– ©2011HongKongEducationalPublishingCo.

There are 36 questions. Questions marked with “*” involve knowledge of the extension component. The back cover of this question paper contains a list of data, formulae and relationships which you may find useful.

1. Four different liquids of equalmass are cooled from the same temperature at the same place for sometime.Which liquidhas thehighest freezingpoint?

A.

B.

C.

D.

2. Whichof the following canbe explainedby thehigh specific heat capacityofwater?

(1) Thebody temperature is regulatedby sweating.(2) The coastal climate ismild comparedwith inland areas on the same latitude.(3) Water is used as a coolant in power stations.

A. (1) onlyB. (3) onlyC. (1) and (2) onlyD. (2) and (3) only

3. Some gas is trapped inside a vessel of fixed volume. If the vessel is heated from 20°C to 120°C,whatwill be thepercentage increase in thegas pressure?

A. 20.0%B. 34.1%C. 100%D. 500%

4. In order to demonstrate the pressure law on nitrogen gas,which of the following precautions should beimplemented?

(1) Thegas temperature shouldbevaried in a high temperature range.(2) Thevolume shouldbekept constant.(3) Thepressure shouldbe increaseduniformly.

A. (1) onlyB. (3) onlyC. (1) and (2) onlyD. (2) and (3) only

*

*

MOCK7PAPER1A-2

– 245 –MOCK 7 PAPER 1B-1

Candidate Number

This paper must be answered in English.

PHYSICS MOCK EXAM 7 PAPER 1SECTION B: Question-Answer Book B

BHONG KONG EDUCATIONAL PUBLISHING CO.

HONG KONG DIPLOMA OF SECONDARY EDUCATION EXAMINATION

©  香港教育圖書公司  保留版權Hong Kong Educational Publishing Co.All Rights Reserved 2011

Marker’sUse Only

Examiner’sUse Only

Marker No. Examiner No.

Question No. Marks Marks

1

2

3

4

5

6

7

8

9

10

11

12

13

Total

Please stick the barcode label here.

INSTRUCTIONS

1. After the announcement of the start of the examination, you should first write your Candidate Number in the space provided on Page 1 and stick barcode labels in the spaces provided on Pages 1, 3, 5 and 7.

2. Refer to the general instructions on the cover of the Question Book for Section A.

3. This section carries 84 marks. Answer ALL questions.

4. Write your answers in the spaces provided in this Question-Answer Book. Do not write in the margins. Answers written in the margins will not be marked.

5. Supplementary answer sheets will be provided on request. Write your Candidate Number, mark the question number box and stick a barcode label on each sheet. Tie them loosely but securely with a string INSIDE this Question-Answer Book.

6. Unless otherwise specified, numerical answers should be either exact or correct to 3 significant figures.

7. The diagrams in this section are NOT necessarily drawn to scale.

8. No extra time will be given to candidates for sticking the barcode labels or filling in the question number boxes after the ‘Time is up’ announcement.

HKDSEPHYPAPER 1

– 246 –

Answers written in the margins will not be marked.

Ans

wer

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the

mar

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be

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Ans

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Page total© 2011 Hong Kong Educational Publishing Co.

Answer ALL questions. Parts marked with “*” involve knowledge of the extension component. Write your answers in the spaces provided.

1. A small ball bearing of mass 30 g is dropped from rest at the mouth of a long glass tube which is partially filled with viscous oil as shown in Figure 1.1. The velocity of the ball bearing varies with time as shown in Figure 1.2.

Figure1.1 Figure1.2

(a) What happens to the bearing at t = 0.6 s? (1 mark)

(b) Find the value of x. (2 marks)

(c) Find the deceleration of the bearing in the oil. (2 marks)

(d) Find the magnitude of the resisting force exerted by the oil on the bearing. (2 marks)

MOCK 7 PAPER 1B-2

– 261 –MOCK 7 PAPER 2-1

Candidate Number

Time allowed: 1 hourThis paper must be answered in English.

PHYSICS MOCK EXAM 7 PAPER 2Question-Answer Book

HONG KONG EDUCATIONAL PUBLISHING CO.HONG KONG DIPLOMA OF SECONDARY EDUCATION EXAMINATION

©  香港教育圖書公司  保留版權Hong Kong Educational Publishing Co.All Rights Reserved 2011

Marker’sUse Only

Examiner’sUse Only

Marker No. Examiner No.

Question No. Marks Marks

Section A1 – 8

Section A9

Section B1 – 8

Section B9

Section C1 – 8

Section C9

Section D1 – 8

Section D9

Please stick the barcode label here.

INSTRUCTIONS

1. After the announcement of the start of the examination, you should first write your Candidate Number in the space provided on Page 1 and stick barcode labels in the spaces provided on Pages 1, 3, 5 and 7.

2. Answer the questions from any TWO sections of this paper.

3. Write your answers in the spaces provided in this Question-Answer Book. Do not write in the margins. Answers written in the margins will not be marked.

4. Supplementary answer sheets will be provided on request. Write your Candidate Number, mark the question number box and stick a barcode label on each sheet. Tie them loosely but securely with a string INSIDE this Question-Answer Book.

5. Unless otherwise specified, numerical answers should be either exact or correct to 3 significant figures.

6. The diagrams in this section are NOT necessarily drawn to scale.

7. The back cover of this question paper contains a list of data, formulae and relationships which you may find useful.

8. No extra time will be given to candidates for sticking the barcode labels or filling in the question number boxes after the ‘Time is up’ announcement.

HKDSEPHYPAPER 2

– 262 –

Answers written in the margins will not be marked.

Ans

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n in

the

mar

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will

not

be

mar

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Ans

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the

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Page total© 2011 Hong Kong Educational Publishing Co.

Section A: Astronomy and Space Science

Given: 1 astronomical unit = 1.50 × 1011 m 1 parsec = 3.08 × 1016 m = 3.26 ly 1 light year = 9.46 × 1015 m

A1.

The figure above shows the Crab Nebula. It is

A. interstellar clouds of gas and dust.B. a solar system.C. a cluster of stars.D. a cluster of galaxies.

Answer:

A2. Stars in the north celestial sphere appear to move around the Polaris because

A. all stars are orbiting around the Polaris.B. the Earth is orbiting around the Sun.C. the Earth is rotating about an axis which passes the Polaris.D. stars in the local group are moving around the centre of the local group.

Answer:

A3. According to the Ptolemaic geocentric model, retrograde motion of Mars

A. can only be explained by the motion around deferent.B. can only be explained by the motion around epicycle.C. can be explained by the motion around both deferent and epicycle.D. can neither be explained by the motion around deferent nor epicycle.

Answer:

A4. Which of the following was not included in Copernican model?

A. The Sun does not orbit around the Earth.B. The Earth is orbiting around the Sun.C. The Moon is orbiting around the Earth.D. Planets orbit around the Sun in elliptical paths.

Answer:

MOCK 7 PAPER 2-2

HKEP

Physics: Mock Exam Papers Solution Guide

– 44 – © 2011 Hong Kong Educational Publishing Co.

Mock Exam 5Paper 1

Section A

1. A

\ E = mc∆T = 1.5 × 4200 × (90 - 55) = 220 500 J

\ Rate of heat released = 22070 60

500×

= 52.5 J s-1

2. CIn a change of state, the separation among the molecules is changed. Thus the potential energy is changed.

3. BBoyles’ law: p1V1 = p2V2

1.5(100%) = p2(88%) p2 = 1.70 atm

4. C

K.E.average = 32RTNA

\ 27°C = 300 K and 327°C = 600 K\ The K.E. at 327°C is twice that at 27°C.

i.e., 12m1v

2 : 12m2crms

2 = 1 : 2

where m1 and m2 are the mass of a H2 molecule and the mass of a 4He molecule.

\ m1 : m2 = 1 : 2

\ 12

(1)v2 : 12

(2)crms2 = 1 : 2

Hence, the root-mean-square speed crms of a 4He molecule at 327°C = v.

5. AThe acceleration due to gravity is always downward. During collision, the ball experiences an upward acceleration for a very short time.

6. CFor (1):Since the parachutist is falling at a high speed, the air resistance is the greatest at the instant the parachute is just fully opened.For (2):The motion is always downward.For (3):The net force is upward in order to decrease such a high falling speed.

Internal energy refers to the

sum of the kinetic energy

of the molecules and the

potent ia l energy among

them.

Te m p e r a t u r e m u s t b e

expressed in the Kelvin scale.

It is not necessary to find

the actual mass (in 10-27 kg)

of a molecule.

The magnitude is constant

(9.81 m s-2) when the object

is close to the Earth.

B e f o r e t h e u s e o f t h e

parachute, the resul tant

force (and acceleration) is

zero because the parachute

is fal l ing with a constant

velocity.

Mock Exam 7

– 81 – © 2011 Hong Kong Educational Publishing Co.

7. (a) Induced e.m.f.

εind

V

= ∆∆

=

= × ×

=

Φt

BAt

6 0 082

0 0603

2( . )

.

π

(b) Resistance R of the loop

=

= × ××

=

−−

ρ lA

( ) ..

.

2 10 2 0 080 5 10

2 01

66

π

Ωε ind

A

===

IRI

I0 0603 2 01

0 03. ( . )

.

(c) Increase the number of turns in the coil.

Understand the physics of electromagnetism. The induced e.m.f. depends on the magnetic flux linkage through the coil.

Be aware of the total length of the wire. The resistivity of a wire is directly proportional to its length.

7. (a) Induced e.m.f.

ε ind

V

= ∆∆

= × ∆ ×

= × × ×

=

Nt

N B At

Φ

50 6 0 042

0 754

2( . )

.

π

1M

1A

(b) Resistance R of the loop

=

= × × × ××

=

−−

ρ lA

( ) ( . ).

.

2 10 50 2 0 040 5 10

50 27

66

π

Ω

1M

1A

Average induced current I =

=

=

ε ind

A

R0 75450 270 0150

..

.

1A

(c) Increase the strength of the magnetic field.Increase the diameter of each loop. 1A(NOT accept: Increase the rotating speed.

Increase the number of turns in the coil.)

This response shows that

the candidate has a basic

knowledge of electricity and

magnetism involved in this

question.

In (a), the candidate makes

a mistake in the equation for

finding the induced e.m.f. by

considering the effect due

to a coil with 1 turn only.

Similarly, the candidate fails

to find the total length of the

coil in (b). Furthermore, the

candidate also misuses the

diameter as the radius in

calculation.

In (c), the candidate does not

understand that increasing

the number of turns in the

coil would also increase the

resistance of the coil.

T h i s r e s p o n s e s h o w s

that the candidate has a

good understanding of the

knowledge of electricity and

magnetism involved in this

question.

In (a) and (b), the candidate

is able to find the induced

e.m.f. and the resistivity by

consider ing the number

of turns in the coi l and

calculating its total length.

In (c), the candidate correctly

s u g g e s t s a m e t h o d t o

increase the total charge

flowing through the coil.

any one