IB Physics Standard Level

Physics SL Exam Skills & Techniques

Master the IB Physics Standard Level exam on the 2023 syllabus. Paper structures, command terms, marking criteria, the Paper 1B data-analysis skills, and the Scientific Investigation IA — everything you need to score top marks.

150 teaching hours • Paper 1 (1A + 1B) + Paper 2 • 1 internal assessment

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Physics SL Assessment at a Glance

36%

Paper 1

1A multiple choice + 1B data • 1h 30m

44%

Paper 2

Short-answer + extended • 1h 30m

20%

Internal Assessment

Scientific Investigation • ≤3,000 words

Physics SL Paper Structure

Know exactly what to expect in each paper and how to maximise your marks.

Paper 1A

Multiple choice

Part of the 1h 30m Paper 1 sitting•25 marks•Paper 1 = 36% of final grade

What to expect:

25 multiple-choice questions, one mark each, no negative marking

Data booklet and a calculator are allowed

Covers the whole SL syllabus across Themes A–E

Sat in the same session as Paper 1B

Key Tips

Answer every question — there is no penalty for a wrong guess, so never leave a blank.
Eliminate obviously wrong distractors first, then check units and orders of magnitude.
Work through quickly: about one minute per question leaves time for Paper 1B.

Easy Marks

Unit and dimension questions you can settle by checking the data booklet
Straightforward substitution into a single equation
Definition-recall items (e.g. which quantity is a vector)

Watch Out

Distractors built from a common slip (forgetting to square, wrong power of ten)
Questions that look like a calculation but only need a proportional reasoning step
Spending too long on one item — flag it and move on, then return

Paper 1B

Data analysis

Part of the 1h 30m Paper 1 sitting•20 marks•Paper 1 = 36% of final grade

What to expect:

Data-based and experimental questions in a structured format

Tests graphing, uncertainties, error bars, and evaluating a method

Data booklet and a calculator are allowed

Sat in the same session as Paper 1A (new in the 2023 syllabus)

Key Tips

Plot points accurately with error bars and draw a clear best-fit line through them.
When asked for a quantity from a graph, read the gradient or intercept and state the unit.
Treat uncertainties methodically: absolute, then fractional, then percentage, then propagate.

Easy Marks

Reading a value or gradient straight off a given graph
Stating the unit of a quantity found from a gradient
Calculating a percentage uncertainty from an absolute uncertainty

Watch Out

Best-fit lines forced through the origin when the data does not support it
Forgetting error bars, or drawing them the wrong size
Vague "improve the experiment" answers — name a specific, realistic change

Paper 2

Short-answer + extended-response

1 hour 30 minutes•50 marks•44% of final grade

What to expect:

A mix of short-answer and extended-response questions

Extended parts are marked on markbands and reward structured reasoning

Covers the whole SL syllabus, often with a quantitative core

Data booklet and a calculator are allowed

Key Tips

Read the command term — "explain", "discuss", and "evaluate" need reasoning, not just a value.
Show every step of a calculation so method marks survive an arithmetic slip.
For extended responses, make one clear physics point per mark available.

Easy Marks

Single-equation calculations with a clear substitution and unit
"State" and "define" parts that test exact IB wording
Drawing or completing a labelled diagram (field lines, free-body, ray diagram)

Watch Out

Losing the unit or significant figures on the final answer
Answering an "explain" with a one-line statement and no reasoning
Running out of time on the extended-response questions — watch the clock

Physics SL Command Terms

Command terms tell you exactly what the examiner expects. Filter by Assessment Objective (AO).

State1 mark

Give a specific name, value, or short answer with no supporting work — e.g. "State the SI unit of magnetic flux density."

Identify1–2 marks

Provide an answer from a number of possibilities — e.g. "Identify the forces acting on the block" on a free-body diagram.

Outline2–3 marks

Give a brief account or summary of the main points — less detail than "describe" — e.g. "Outline how a transformer steps up voltage."

Describe2–4 marks

Give a detailed account of what happens, in words — e.g. "Describe the motion of the ball" or "Describe the energy changes."

Draw1–3 marks

Represent by a labelled, accurate diagram or graph using a pencil — e.g. "Draw the field lines between the plates" with arrows and direction.

Sketch2–3 marks

Represent by a graph showing the key shape, intercepts, and trend — proportions roughly to scale, labelled axes — e.g. "Sketch how acceleration varies with time."

Calculate2–4 marks

Obtain a numerical answer showing the relevant working, the correct unit, and an appropriate number of significant figures.

Determine2–4 marks

Obtain the only possible answer — often from a graph (gradient or area) or by combining several equations — and justify how it is fixed.

Estimate2–3 marks

Find an approximate value, often using sensible assumptions or an order-of-magnitude calculation — e.g. "Estimate the kinetic energy of the car."

Show that2–4 marks

The result is printed in the question — derive it from first principles, showing every step. Carry one more significant figure than the given value to prove it.

Deduce2–4 marks

Reach a conclusion from the information given, stating the reasoning — e.g. "Deduce whether the collision is elastic" using a momentum or energy argument.

Explain3–5 marks

Give a detailed account of causes and reasons, linking physics principles to the situation — the word "because" should appear in your answer.

Suggest2–3 marks

Propose a hypothesis, improvement, or explanation for an unfamiliar situation — common in the Paper 1B "suggest an improvement to the method" question.

Discuss3–6 marks

Give a balanced, reasoned argument considering more than one factor or point of view, then reach a supported judgement.

Evaluate3–6 marks

Weigh up strengths and limitations to reach an overall judgement — common when assessing a method, a model, or a set of results.

What Examiners Expect

Match your answer depth to the marks available.

Method / working marksAwarded for the correct substitution into the right equation, even if the arithmetic that follows is wrong.

Example questions:

"Substituting correctly into v² = u² + 2as before solving"
"Resolving a force into components before applying ΣF = ma"
"Reading the correct gradient or area from a graph"

Always write the equation and the substitution on separate lines — you earn the method mark even when the final number is wrong.

Error carried forward (ECF)A wrong value from an earlier part is accepted as the input to a later part — you keep the marks for the later method.

Example questions:

"Using your (incorrect) velocity from part (a) correctly in part (b)"
"Carrying a mis-read gradient forward into the final quantity"

A slip in part (a) usually only costs one mark — keep going and use your own answer; ECF protects every later part.

Significant figures & unitsThe final answer must carry a correct unit and a sensible number of significant figures (usually 2–3, matching the data).

Example questions:

"Quoting 4.9 m s⁻² rather than 4.90000 m s⁻²"
"Including the unit on every final quantity (N, J, V, T …)"
"Matching the s.f. of the answer to the least precise data given"

A missing or wrong unit, or a wildly wrong number of significant figures, loses the final mark even when the value is correct.

"Show that" / reasoning marksIn a "show that" the answer is given, so marks come from a complete chain of working; AO3 reasoning marks need explicit because-statements.

Example questions:

"Deriving a = g sinθ line by line, ending one s.f. beyond the printed value"
"Stating "the resultant force is zero, therefore the object is in equilibrium""
"Linking each step in an explanation to a named physics principle"

Never work backwards from the printed answer — derive it forward, and in "show that" quote one extra significant figure to prove you reached it.

Physics SL-Specific Skills

These concepts appear throughout Physics SL exams. Master them to score higher.

Always draw a free-body diagram

Before any mechanics calculation, draw the object as a dot and add every force as a labelled arrow from that dot. It stops you missing a force (weight, normal, tension, friction) and makes resolving into components obvious.

Gradient vs area — read the axes first

On a motion or field graph, the gradient and the area mean different physical quantities. On a v–t graph the gradient is acceleration and the area is displacement. Always check the axis labels and units before deciding which one the question wants.

Carry units and significant figures

Every final answer needs a unit and a sensible number of significant figures (usually matching the data, 2–3 s.f.). Convert to SI base units (kg, m, s) before substituting, and only round at the very end.

Vector or scalar? It changes the method

Decide whether each quantity is a vector (displacement, velocity, force, momentum, field) or a scalar (distance, speed, energy, mass). Vectors must be added with direction or by components; treating a vector as a scalar is a classic lost-marks error.

Master the data booklet

The physics data booklet is provided in every paper and holds the equations, constants, and unit prefixes. Learn where each equation lives and which relationships you must rearrange yourself so you never waste time hunting for them.

Practise the Paper 1B data skills

Paper 1B is data-based: plotting with error bars, drawing best-fit and steepest/shallowest gradient lines, propagating uncertainties, and suggesting method improvements. These experimental skills also carry the Internal Assessment, so drill them early.

Common Physics SL Mistakes to Avoid

Learn from others' mistakes. These cost students marks every exam session.

Forgetting units or quoting too many significant figures

End every final answer with the correct unit and round to a sensible number of significant figures (usually 2–3, matching the data). A missing unit loses the final mark.

Reading a graph gradient when the area is wanted (or vice versa)

Check the axis labels first. On a velocity–time graph the gradient is acceleration and the area underneath is displacement — they are not interchangeable.

Treating a vector as a scalar

Velocity, force, and momentum have direction. Add them by components or with a vector triangle; never just add or subtract the magnitudes when directions differ.

Leaving forces out of a free-body diagram

Draw the body as a dot and add weight, normal/reaction, tension, and friction as separate labelled arrows. A missing force gives the wrong resultant.

Mixing up units before substituting

Convert to SI base units first — grams to kilograms, centimetres to metres, kilometres per hour to metres per second — before putting numbers into an equation.

Getting the sign convention wrong

Choose a positive direction at the start of a problem and stick to it. In projectile and energy questions, deceleration, downward displacement, and energy lost are negative relative to that choice.

Writing a one-word answer to "explain", "discuss", or "evaluate"

These AO3 command terms need reasoning. Link each point to a physics principle with a because-statement, and for "discuss"/"evaluate" give both sides before a judgement.

Working backwards from the printed answer in "show that"

Derive the result forward from first principles and quote one extra significant figure beyond the given value to prove you actually reached it.

Scientific Investigation

20% of final grade • ≤ 3,000 words

A single individual investigation (about 10 hours of work) in which you plan and carry out your own experiment on a physics research question, then write it up as a report. SL and HL students do exactly the same task, marked on the same four criteria out of 24.

Marking Criteria

Research design6 marks

Data analysis6 marks

Conclusion6 marks

Evaluation6 marks

Tips for Top Marks

Choose a focused research question with a clear independent and dependent variable, and state how you will control the others (Research design).
Plan enough data: at least five values of the independent variable with repeats, so you can plot a meaningful graph with error bars.
Process uncertainties properly — show absolute, fractional, and percentage uncertainty and propagate them into your final result (Data analysis).
Link your conclusion to accepted physics and, where possible, to a literature or theoretical value, commenting on agreement within uncertainty (Conclusion).
Evaluate honestly: identify specific systematic and random sources of error, judge their impact, and suggest realistic, targeted improvements (Evaluation).
Keep it to 3,000 words — examiners reward a focused, well-analysed investigation over a long, padded one.

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Physics SL Exam Skills & Techniques

150 teaching hours • Paper 1 (1A + 1B) + Paper 2 • 1 internal assessment