G3 Physics / O-Level Physics Practical Skills
G3 Physics and O-Level practical skills: planning, measurement, data presentation, analysis and experimental evaluation.
Learning goals
- Measurements of length, mass, temperature, time interval, volume of liquids/solids and force (e.g. weight) using appropriate instruments
- Determination of the density of a liquid, or of a regularly or irregularly shaped solid that sinks in water
- Determination of the value of the acceleration of free fall
- Investigation of the effects of balanced and unbalanced forces
- The principle of moments
- Determination of the position of the centre of gravity of a plane lamina
- Investigation of the factors affecting transfer of energy by thermal processes
- Determination of heat capacities of materials
- Latent heat of substances
- The law of reflection
- Determination of the position and characteristics of an optical image formed by a plane mirror or a thin converging lens
- The refraction of light through glass blocks
- The principle of total internal reflection
- The focal length of lenses
- Determination of the speed, wavelength and frequency of waves
- Determination of the resistance of a circuit component
- Investigation of the magnetic effect of current in a conductor
- Investigation of the effects of electromagnetic induction
The G3 Physics and O-Level Physics practical papers use the same duration, marks, weighting and four skill areas, so this sequence is useful for both courses. G3 Physics students should begin with the lesson on all 18 required practical contexts, then strengthen the skills used in every investigation.
Follow this order:
- Learn the methods and reasoning for the 18 G3 Physics practical contexts.
- Plan a fair and safe investigation.
- Set up apparatus and make reliable measurements.
- Present readings, analyse evidence, conclude and evaluate.
Revise the Measurement Hub first if instrument range, resolution, parallax or zero error is unfamiliar.
Lessons
Paper 3 skill areas
Required practical work
Methods, reasoning, calculations and common mistakes for all 18 practical contexts named in K323.
Planning an investigation
Identify variables, select apparatus, write a reproducible method and match risks to precautions.
Manipulation, measurement and observation
Follow instructions, set up apparatus and record observations with justified precision.
Presenting practical data
Construct tables, process readings, choose graph scales and calculate a defensible gradient.
Analysis, conclusions and evaluation
Use evidence for conclusions, identify significant errors and propose matched improvements.
Applied technique refreshers
Measuring length
Choose suitable range and resolution and use rules, calipers and micrometers correctly.
Measuring time
Time intervals and repeated oscillations while reducing reaction-time effects.
Accuracy, precision and errors
Distinguish random and systematic effects and match each source to a correction.
Plotting graphs from data
Choose scales and distinguish exact connections from an experimental best-fit trend.
Density practical
Determine volume by dimensions or displacement and calculate density consistently.
Laboratory thermometer
Use suitable immersion, equilibrium and eye-level reading technique.
Cooling-curve data
Record and interpret temperature–time trends and state-change plateaux.
What the lessons teach
| Practical skill | Main lesson |
|---|---|
| follow instructions and use apparatus safely | Manipulation, measurement and observation |
| make and record observations, measurements and estimates | Manipulation, measurement and observation and Presenting practical data |
| interpret and evaluate observations and results | Presenting practical data and Analysis, conclusions and evaluation |
| plan investigations and select suitable techniques, apparatus and materials | Planning a Physics investigation |
| identify limitations and suggest specific improvements | Planning a Physics investigation and Analysis, conclusions and evaluation |
The practical paper organises these skills into four areas: Planning (P), Manipulation, Measurement and Observation (MMO), Presentation of Data and Observations (PDO), and Analysis, Conclusions and Evaluation (ACE). Planning has a 15% weighting within the paper; MMO, PDO and ACE together have 85%.
Revision
Paper 3 format
- Duration: 1 h 50 min.
- Total: 40 marks, worth 20% of each course.
- Section A: 20 marks and 55 minutes of practical work across one or two questions.
- Section B: 20 marks and one compulsory 55-minute practical question.
- Planning may be assessed in one or more questions; PDO and ACE may include data analysis without apparatus.
Cross-topic practical contexts
For G3 Physics, the required practical work lesson brings all 18 named contexts together. Use these shorter lessons when you want to revisit the physics behind one method:
- Measurement and mechanics: length, time and period, density, free fall, moments, centre of gravity.
- Thermal physics: laboratory thermometer, thermal transfer, heat capacity, latent heat.
- Waves and optics: ripple tank, reflection, refraction, total internal reflection, converging lenses.
- Electricity and magnetism: resistance, current-produced magnetic fields, electromagnetic induction.
Follow the question’s written instructions and the centre’s safety arrangements. Do not improvise heating, mains-electricity or radiation procedures. Name only credible hazards and controls for the apparatus provided.
Fast Paper 3 checks
- Plan: identify the independent variable, dependent variable and relevant controls; state measurements, range, repeats, processing and a matched risk control.
- Measure: check zero, range, eye position, unit and whether the reading is steady.
- Present: use quantity/unit headings, consistent raw precision, sensible graph scales and a large gradient triangle.
- Evaluate: write source → effect → matched improvement; do not use “human error” or “repeat” as universal answers.
Practice
- Complete one timed plan from an unfamiliar setup and mark every variable, measurement and control explicitly.
- Use Plotting Kinematics Graphs from Data to practise scale choice and best-fit decisions.
- Finish with Mock Paper 2 Structured Practice for transferable data-analysis reasoning.
Continue learning
- Return to the G3 Physics / O-Level Physics portal to revise the content behind an unfamiliar practical context.
- O-Level students can use the O-Level Exam Skills Hub for command words, units and structured-response technique.
Continue with the next resource in this course.
Course and syllabus information
- Course
- SEC G3 Physics
- Edition
- SEC G3 Physics 2027