PHYSICS · HKDSE
PHYSICS/21
(Elective Curriculum)
Physics · 2021 · Variant 1
Relative difficulty
Analysis source: Hong Kong Examinations and Assessment Authority (HKEAA)
Analysis aligned to the official syllabus and assessment design.
3.6 / 5
153
210 min
Light: Refraction, Lenses and Wave Optics
Cohort performance
Session statistics from official examination reports
Total marks
153
Duration
210 min
Session difficulty
3.6 / 5
Level 5**
~90% of max
Level 5*
~86% of max
Level 5
~68% of max
Key examiner messages
Top priorities from the principal examiner before you revise
The 2021 Physics paper was moderately challenging, requiring a robust conceptual framework rather than mechanical formula application. Section A (MC) contained several distractor-heavy questions (such as Q22 on electric fields and Q26 on induced e.m.f.) that tested edge cases, wh
Section A (MC) contained several distractor-heavy questions (such as Q22 on electric fields and Q26 on induced e.m.f.) that tested edge cases, while Section B combined experimental evaluation with standard analytical calculations.
Question difficulty map
How candidates performed on each question in this series
No data available in official reports
Assessment objectives
Skill and AO weighting from official examiner commentary
Skill weighting
Shows the skill mix this paper tested most heavily.
Mathematical
Weight: 6100%Graphical
Weight: 583%Drawing
Weight: 467%Qualitative Explanation
Weight: 350%Experimental
Weight: 117%
Method marks watchlist
Where working, steps, or method marks were commonly lost
No data available in official reports
Recurring mistakes across years
Themes examiners flag in multiple recent sessions for this subject
No data available in official reports
Question choice intelligence
Mean scores and popularity for optional questions (HKDSE electives)
No data available in official reports
Level exemplars
What candidate scripts at each grade level looked like
No data available in official reports
Grade & admission context
How marks relate to grade thresholds and entry standards
Reporting source
HKEAA Subject Examination Report — comments on candidates’ performance with marking schemes
Level 5**
Outstanding — competitive JUPAS programmes (medicine, law, top faculties)
Level 5*
Excellent — strong JUPAS profile for selective programmes
Level 5
Good — meets most university entrance requirements
Level 4
Satisfactory — foundation programmes or less selective routes
Level 3
Pass threshold for many sub-degree and vocational pathways
Admission context
Levels feed JUPAS and non-JUPAS university applications; 5** and 5* are most selective
Deep insights
What top candidates did
Techniques and approaches examiners rewarded in this series
No data available in official reports
Command word playbook
How to match each command word to the expected response style
Match the expected response style for “Find” questions.
Support your choice with specific evidence from data or the scenario given.
Match the expected response style for “Prove” questions.
Match the expected response style for “Deduce” questions.
Time traps
Sections where candidates spent disproportionate time relative to marks
Min per mark: 1.8
Min per mark: 1.6
Syllabus traceability
Topics linked to questions and mark weighting in this session
Light: reflection, refraction, diffraction, lenses (Wave Motion)
19 marks this session
Circuits and Domestic Electricity (Electricity and Magnetism)
13 marks this session
Projectile Motion (Force and Motion)
11 marks this session
Electromagnetism & electromagnetic induction (Electricity and Magnetism)
11 marks this session
MCQ trap analytics
Commonly chosen wrong options from examiner commentary
No data available in official reports
Topic heatmap across years
Mark concentration by topic and exam year for this subject
Mark intensity
Light: reflection, refraction, diffraction, lenses (Wave Motion)
Circuits and Domestic Electricity
Circuits and Domestic Electricity (Electricity and Magnetism)
Electromagnetism & electromagnetic induction (Electricity and Magnetism)
Nature and Properties of Waves
Electromagnetism & electromagnetic induction
Photoelectric effect (Atomic World Elective)
Light: reflection, refraction, diffraction, lenses
Difficulty trend
How session difficulty has shifted across recent years
Paper comparison
Marks and duration breakdown across papers in this session
Paper 1 (Compulsory Section):
Paper 2 (Elective Section - 2 of 4 Chosen):
Marks you can still earn
Where valid approaches outside the mark scheme may still gain credit
No data available in official reports
Practise what examiners flagged
Target weak topics from this report inside the Revui app
Light: reflection, refraction, diffraction, lenses (Wave Motion)
19 marks this session
Practise in RevuiCircuits and Domestic Electricity (Electricity and Magnetism)
13 marks this session
Practise in RevuiProjectile Motion (Force and Motion)
11 marks this session
Practise in RevuiElectromagnetism & electromagnetic induction (Electricity and Magnetism)
11 marks this session
Practise in RevuiSelf-diagnostic checklist
Key actions before you sit this paper — copy and tick off as you revise
- 1Message
The 2021 Physics paper was moderately challenging, requiring a robust conceptual framework rather than mechanical formula application. Section A (MC) contained several distractor-heavy questions (such as Q22 on electric fields and Q26 on induced e.m.f.) that tested edge cases, wh
- 2Message
Section A (MC) contained several distractor-heavy questions (such as Q22 on electric fields and Q26 on induced e.m.f.) that tested edge cases, while Section B combined experimental evaluation with standard analytical calculations.
Teacher briefing pack
One-page session summary for tutors and classroom review
2021 2021
Physics
The 2021 Physics paper was moderately challenging, requiring a robust conceptual framework rather than mechanical formula application. Section A (MC) contained several distractor-heavy questions (such as Q22 on electric fields and Q26 on induced e.m.f.) that tested edge cases, wh
The 2021 Physics paper was moderately challenging, requiring a robust conceptual framework rather than mechanical formula application. Section A (MC) contained several distractor-heavy questions (such as Q22 on electric fields and Q26 on induced e.m.f.) that tested edge cases, wh
Section A (MC) contained several distractor-heavy questions (such as Q22 on electric fields and Q26 on induced e.m.f.) that tested edge cases, while Section B combined experimental evaluation with standard analytical calculations.
- Total marks
- 153
- Duration
- 210 min
- Session difficulty
- 3.6 / 5
- Level 5**
- ~90% of max
- Level 5*
- ~86% of max
- Level 5
- ~68% of max
Session analysis
The 2021 Physics paper was moderately challenging, requiring a robust conceptual framework rather than mechanical formula application. Section A (MC) contained several distractor-heavy questions (such as Q22 on electric fields and Q26 on induced e.m.f.) that tested edge cases, while Section B combined experimental evaluation with standard analytical calculations.
Updated Jun 11, 2026
Paper breakdown
Paper 1 (Compulsory Section):
Paper 2 (Elective Section - 2 of 4 Chosen):
Top chapters
Exam structure insights
Marks by chapter
See where the marks were concentrated so revision time goes to the highest-value topics.
Mark accessibility
Estimate which marks were basic, mid-level, or high-difficulty.
78% within easy or medium reach
Command word frequency
Spot common command words so answers match the expected response style.
Question type mix
Compare the mark share of each paper section and question type.
Conventional
(Structured/Long Questions)
84·9·55%
Multiple Choice
(MC)
49·49·32%
Elective Long Questions
20·2·13%
Study ROI
Bigger bubbles recur more often; higher bubbles carry more marks, helping you rank revision priorities.
Time vs marks
Compare marks with suggested time allocation to plan exam pacing.
Paper 1 Section A (…
— m/minPaper 1 Section B (…
0.64 m/minPaper 2 (Electives …
0.57 m/minTotal marks
877
Total time
60 min
Avg pace
14.62
Next-year prediction
Topics worth watching next year, with the reason shown directly below each bar.
Electromagnetism & electromagnetic induction
90%90%
Photoelectric effect (Atomic World)
85%85%
Difficulty Verdict
The 2021 Physics paper was moderately challenging, requiring a robust conceptual framework rather than mechanical formula application. Section A (MC) contained several distractor-heavy questions (such as Q22 on electric fields and Q26 on induced e.m.f.) that tested edge cases, while Section B combined experimental evaluation with standard analytical calculations.
Examiner notes & key calculations
- Misunderstanding Insulation: In Q1(d), many candidates incorrectly justified the use of a copper cup, failing to recognize that copper's high thermal conductivity would increase heat loss to the surroundings compared to polystyrene.
- Tension in Dynamic Systems: In Q4(a)(ii), many fell into the classic trap of assuming string tension equals the weight of the hanging mass, neglecting the downward acceleration.
- Neglecting Boundary Conditions: In Q2(c)(ii), candidates struggled with the inequality for inflating balloons, forgetting that gas cannot be transferred once the cylinder pressure falls to the ambient seabed pressure (4.0 atm).
Exam tips
Paper format
- Duration
- 1h
- Total marks
- 36
- Weighting
- 20%
- Question types
- MCQ, Structured Question
Analysis is paraphrased for study purposes. Always verify against the official examiner report and mark scheme.