The Mark-Maximising Philosophy
Every mark in IB Physics has a specific trigger — a word, a number, a unit, a drawn line — that tells the examiner to award it. Your job is to hit as many triggers as possible in every answer.
This guide focuses exclusively on what earns marks, not what earns understanding (though they often overlap).
The 10 Easiest Marks to Collect
These are marks that require minimal physics knowledge but are dropped by the majority of students:
1. Write Units (1 mark per calculation)
Every calculation answer needs a unit. “F = 24” is incomplete. “F = 24 N” earns the unit mark.
2. State the Equation (1 mark per calculation)
Writing “F = ma” before substituting earns the equation mark, even if your final answer is wrong.
3. Label Graph Axes (1 mark per graph)
Both axes need: quantity / unit (e.g., “Displacement / m”). No unit = no mark.
4. Draw Construction Lines on Graphs (1 mark)
When reading a value from a graph, draw a horizontal and vertical line to the axes. This earns the “method” mark.
5. Include Direction for Vectors (1 mark per answer)
“The force is 24 N” is incomplete for a vector. “The force is 24 N downward” is complete.
6. Use the Word “Because” in Explanations
“The current decreases because the resistance increases” earns a link mark. “The current decreases. The resistance increases.” might not — the causal connection is missing.
7. Show Substitution (1 mark per calculation)
After writing the equation, show the numbers going in: “F = (2.0)(9.81) = 19.6 N”
8. Answer in the Space Provided
If the answer space is 3 lines, write approximately 3 lines. If it’s half a page, write half a page. The space is designed to match the expected depth.
9. Define Terms When Asked
“State” and “define” have specific mark scheme answers. Memorise the syllabus definitions for: force, work, power, energy, field strength, potential, etc.
10. Attempt Every Question
There is no penalty for wrong answers. Even a guess can earn a mark if it’s partially correct or triggers ECF in later parts.
Mark Collection by Paper
Paper 1A
- 30 marks available (SL) / 40 marks (HL)
- Each question worth 1 mark
- Strategy: Eliminate first, then choose. Never leave blank.
- Target: 25/30 (SL) or 32/40 (HL)
Paper 1B
- 25 marks available
- Structured questions with mark allocations shown
- Strategy: State equations, show substitutions, include units
- Target: 18/25
Paper 2
- 50 marks available (SL) / 80 marks (HL)
- Extended response and data analysis
- Strategy: Graph work is predictable — practise it. Evaluation answers follow a template.
- Target: 35/50 (SL) or 56/80 (HL)
IA
- 24 marks available
- You control the quality — no time pressure, no surprises
- Strategy: Follow the criteria checklist exactly
- Target: 20/24
The Error Carried Forward Advantage
ECF (Error Carried Forward) means that if you get part (a) wrong but use your wrong answer correctly in part (b), you can still earn full marks for part (b).
This means: Never skip a multi-part question just because you’re unsure about part (a). Attempt every part.
Example:
- Part (a): Calculate the acceleration. Student gets 8.5 m/s² (correct: 9.81 m/s²)
- Part (b): Using your answer from (a), calculate the force on a 5 kg mass.
- Student writes: F = ma = 5 × 8.5 = 42.5 N → Full marks for part (b) via ECF
Communication Marks
In extended response questions, marks are reserved for:
- Using correct scientific terminology (not “stuff” but “charge carriers”)
- Logical structure (cause → effect → conclusion)
- Referencing the question context (not generic physics)
These marks distinguish Level 2 (3–5 marks) from Level 3 (6–8 marks) responses.
The Pre-Exam Mark Audit
Before each exam, review:
- Can I state and substitute into all common equations?
- Do I know the IB definitions for key terms?
- Can I construct a graph with labels, error bars, and best-fit line?
- Can I write a causal explanation with correct terminology?
- Do I have a time plan for each paper?