Before you think about that exam paper, take a moment to acknowledge what brought you to this point. You have invested time, effort, sacrifice and sheer hard graft in getting to grips with this demanding subject. Think of the ideas you have wrestled with, the questions you have practised and the evenings you have given over to revision. You have clearly earned your foothold in physics, and you should feel rightly proud of that achievement.
By now, you know a great deal about the subject. Your next task is to demonstrate it to someone who also understands it: your examiner. Spare a thought for them when you begin your long, well-deserved summer break. They will still be diligently working through examination papers, applying the same marking criteria and giving every student the same fair consideration.
But remember: while it is quite right to assume their expertise, it remains a common misconception they will use their understanding to wave an incomplete answer through. An examiner can only ever award marks for what you present.
The recurring themes in examiners’ reports offer useful insight for students aiming for the highest grades. Over the years, I have read many of these and continue to be struck by the common shortcomings found year to year in candidates’ answers. As a response to this, I have written down the following ten habits that I would encourage you to consistently apply. Whether you are beginning Year 12 or approaching your final examinations, these will help you prove what you know.
10. Keep your precision until the end
When you have worked hard to understand a calculation, losing marks through premature rounding is particularly frustrating. Keep the full value in your calculator as you move between steps, then round your final answer to an appropriate number of significant figures. For example, if you calculate a current of 0.1467 A before finding the power, carry that value forward rather than rounding it to 0.15 A. Remember that the precision of your final answer should reflect the data you have been given. Check your units too, converting measurements such as millimetres or milliseconds into appropriate SI units before substituting them into equations. Give your calculations the accurate starting points they deserve.
9. Let the examiner follow your method
Let your working tell the full story of how you reached your answer. Set out the relevant equation, substitute your values and show the main stages in a logical order. When, for example, calculating an object’s speed from its kinetic energy, show how you rearranged the relationship before entering the numbers. If an arithmetic slip follows, the examiner may still be able to credit the successful stages. Clear working also makes it easier for you to spot your own mistake before moving on.
8. Get comfortable with precise definitions
Physics gives familiar words such as power, energy and potential specific meanings. Take time to understand those meanings and express them accurately. For example, electric field strength describes the force per unit positive test charge at a point. Leaving out “positive” renders this definition incomplete. When you revise, try explaining a term aloud and then checking it against the definition, paying attention to the details that make it complete.
7. Ask what the graph is telling you
A graph presents evidence about a physical situation, and its shape deserves your attention before you start calculating. Look at the axes, check the units and ask what the gradient or area represents. The gradient of a velocity–time graph gives acceleration, while the area below the line is the displacement. If you need the acceleration at one instant on a curved graph, draw a tangent there and calculate its gradient. That short pause to interpret the graph can save you a much longer journey down the wrong route.
6. Discover why the experiment works
During practical sessions, I would encourage you to be curious about every decision in the method. Ask why you are using a particular instrument, what you need to control and how your measurements will produce the required result. For example, measuring a wire’s diameter allows you to calculate its cross-sectional area when investigating resistivity. Taking measurements at several positions also helps you assess how uniform the wire is. Understanding those choices prepares you for questions that place familiar practical skills in a different arrangement.
5. Make your practical improvements specific and consider uncertainties
When you suggest an improvement, explain which limitation you are addressing and how your change helps. Imagine you are measuring the period of a pendulum using a stopwatch. Timing 20 oscillations and dividing by 20 reduces the percentage uncertainty associated with reaction time compared with timing one oscillation. Your timing interval becomes much longer while the reaction-time uncertainty remains approximately the same. An answer like that shows the examiner that you understand both the problem and the purpose of your solution.
4. State clearly what your result establishes
Sometimes your calculation gives you the evidence for an answer, but you still need to explain the conclusion. Suppose you find that a cable would experience a tension of 450 newtons, while its stated maximum safe tension is 400 newtons. Compare those figures and explain that the predicted tension exceeds the safe limit. You have now answered the practical question behind the calculation. Before leaving a numerical problem, look back at the wording and check whether it asks you to make a judgement.
3. Take your explanation all the way through
The importance of clear explanations cannot be overemphasised. If ever a subject owed as much to the why as the what, it is ours. For example, a cushion increases stopping time during an impact; for the same change in momentum, that longer stopping time reduces the mean force. This would be a nice opportunity to mention that this links to Newton’s 2nd law. Each link earns its place by explaining the next.
2. Picture the physics before picking the equation
When you recognise familiar quantities, reaching straight for an equation can feel reassuring. But first, give yourself time to picture what is happening and identify the principle(s) that governs it. The standard SUVAT equations require constant acceleration, so you need to check that condition before using them. In a collision, momentum may be conserved while kinetic energy decreases. A sketch and a few seconds of thought can help you choose an approach that fits the situation, particularly when the question looks unfamiliar.
…and finally, at number 1: ANSWER THE QUESTION ON THE PAGE
My final advice is always to read the task carefully before letting your knowledge rush ahead of you. Identify what you are being asked to explain, calculate or justify, and pay attention to the particular conditions. Explaining gas pressure, for example, through molecular behaviour requires you to discuss collisions and momentum transfer; quoting a gas law leaves that mechanism unexplained. Watch for small words such as “initial” and “change”, because they can alter the answer required. Before you move on, check that you have given your examiner exactly the evidence the question requested.
Take a Breath, then take the next step
You have chosen a subject that asks a great deal of you, and you should be proud of the progress you have made. Every difficult idea you master and every answer you improve adds to that achievement. Keep practising these habits so that your examination paper reflects the true understanding you have worked so hard to develop.
To further build your understanding of the subject, consider visiting my virtual physics lab, where you can effortlessly change variables, predict the effects and check what happens. It is a practical way to explore the physics behind the equations and strengthen your grasp of the ideas.
I hope you have found these suggestions helpful. For students looking to take their understanding of physics further, private physics tutoring can provide more personalised support. As I explored in my article on why good students use private physics tutoring, even students who are already achieving excellent results can benefit from additional guidance.