Physics — Exam Writing Tips
How to write Physics answers for full marks in TGBIE — presentation tips for derivations, numericals, conceptual questions, and diagrams.
General Strategy for Physics Paper
- 1Physics paper: Section A (very short, 2m each × 10), Section B (short, 4m each, attempt 5 from 8), Section C (long, 7m each, attempt 5 from 7). Always attempt Section A fully.
- 2For numerical problems: write Given data, To find, Formula, Substitution, Calculation, Result with units — all clearly. Missing units costs marks.
- 3For 7-mark derivations: marks are awarded stepwise. Even if your final answer is wrong, partial marks for correct steps are given.
- 4Draw diagrams wherever relevant — even if not explicitly asked. A neat labelled diagram earns marks and shows understanding.
Derivations — How to Write
- 1Start with the physical situation: 'Consider a body of mass m moving with initial velocity u under uniform acceleration a.'
- 2State each step as an equation. Don't skip algebra steps — write (1), (2), (3) for intermediate equations.
- 3End the derivation clearly: 'Therefore, v² = u² + 2as. This is the third kinematic equation of motion.'
- 4For kinematic equations, projectile formulas, orbital velocity, Carnot efficiency — these are the most common LAQs. Practice until you can write them in 6 minutes.
- 5Mention the physical significance of the result (e.g., for escape velocity: 'A body projected with this velocity escapes Earth's gravitational field').
Numerical Problems — How to Write
- 1Always write SI units in the Given section. Convert km/h to m/s (÷ 3.6), g to kg, cm to m before solving.
- 2For projectile problems: identify θ, u, and what is asked. Write the relevant formula, then substitute.
- 3For SHM numericals: first find ω = 2π/T, then use v = ω√(A²−x²) or E = ½mω²A².
- 4For Carnot engine: write η = 1 − T₂/T₁. Remember temperatures must be in Kelvin (T(K) = T(°C) + 273).
- 5Verify your answer has the right unit. Energy must be in Joules, force in Newtons, pressure in Pascals.
Conceptual Questions — How to Write
- 1Define the quantity first (e.g., 'Moment of inertia is the resistance of a body to rotational motion about a given axis'), then state the formula.
- 2For 'Explain with example' questions: give a real-world example (e.g., ice skater for angular momentum conservation).
- 3For 'State and explain the law' questions: state the law as a complete sentence, then explain the physical significance.
- 4For comparison questions (e.g., 'elastic vs inelastic'): use a two-column format or numbered points.