Overview
Understanding the specific meaning of command words is one of the most effective ways to improve your marks in Cambridge A-Level Physics (9702). These words are the examiner's direct instructions, telling you exactly what type of answer is required and how much detail to provide. Misinterpreting a command word can mean you write a perfect answer to the wrong question, so mastering them is essential for success across Papers 1, 2, 3, 4, and 5.
The 'Recall' Command Words: Define, State, and List
For Cambridge syllabus 9702, these are the most straightforward command words, typically used for lower-tariff questions that test your foundational knowledge. When you see Define, the examiner expects a formal, concise definition of a term, just as you would find it in a textbook. For example, defining 'potential difference' requires the 'work done per unit charge' phrase; no more, no less. State asks for a specific piece of information without any supporting explanation, such as stating a principle or the value of a constant. Similarly, List requires you to provide a number of points, often best presented as a bulleted list for clarity, without the need for full sentences or justifications. For these questions, adding extra information will not gain you more marks and only wastes valuable exam time.
The 'Show and Tell' Command Words: Describe and Explain
For Cambridge syllabus 9702, moving up in complexity, Describe and Explain ask for more developed answers. Describe requires you to give a detailed account of something – what happens in a process, what a graph looks like, or the key features of a phenomenon. For instance, describing the motion of a ball thrown upwards would involve detailing its velocity changes at different points in its trajectory. Explain, however, demands a deeper level of understanding by asking *why* or *how* something happens. An explanation must link cause and effect using underlying physics principles or laws. To explain the motion of the same ball, you would need to reference the constant downward force of gravity causing a constant downward acceleration, thereby changing the ball's velocity.
The 'Calculation' Command Words: Calculate, Determine, and Show that
For Cambridge syllabus 9702, these command words are central to the quantitative side of physics. Calculate is a direct instruction to find a numerical answer from given data. To secure all marks, you must show your working clearly: write the formula, substitute the values correctly, and give the final answer with the correct unit and to an appropriate number of significant figures. This methodical approach is a core part of the [9702 marking criteria](/subjects/9702). Determine is often used when a value must be found from a graph (e.g., finding the gradient) or derived from experimental results, implying a step of data processing is needed before the calculation itself. Show that questions provide the final answer, and your task is to present a clear, logical sequence of steps that leads to it. It’s crucial to show all your working and not skip any algebraic steps, as the process is what is being marked.
The 'Higher-Order' Command Words: Suggest and Compare
For Cambridge syllabus 9702, these command words test your ability to apply your knowledge in new or slightly unfamiliar contexts. Suggest invites you to put forward a reasoned idea or hypothesis. There might be several valid answers, but your proposal must be scientifically plausible and supported by a clear justification based on physics principles. This is common in questions about experimental errors or modifications to an experiment. Compare requires you to give both the similarities and the differences between two or more concepts, objects, or phenomena. A frequent mistake is to only list the differences. To score well, you should address both aspects systematically; a side-by-side table can be an effective way to structure your answer and ensure you cover both sides.
The 'Top-Tier' Command Words: Discuss, Evaluate, and Assess
For Cambridge syllabus 9702, found in high-tariff questions, especially in Paper 4, these command words demand the most sophisticated response. Discuss, Evaluate, and Assess all require you to explore a topic from multiple viewpoints, considering the pros and cons, or arguments for and against a particular statement. You must present a balanced argument, weighing up different factors or evidence. However, the most crucial element for reaching the top mark bands is to provide a final, supported judgement or conclusion. Simply listing points is not enough; you must synthesise them to arrive at a well-reasoned final decision. For a broader look at these types of questions across different Cambridge subjects, our general guide to [command words explained](/blog/cambridge-command-words-explained) is a useful resource.
Frequently asked questions
This section covers Frequently asked questions — ranked by what Cambridge examiners return to most often in past papers.
How many significant figures should I use in my calculations?
As a general rule, your final answer should be given to the same number of significant figures as the least precise data value used in the calculation, which is typically 2 or 3 s.f. in exam questions. In 'Show that' questions, keep more significant figures in your working to avoid rounding errors that prevent you from reaching the given answer.
What's the real difference between 'Describe' and 'Explain'?
'Describe' asks you to state what happens. For example, "As the thermistor's temperature increases, the resistance decreases." 'Explain' asks why it happens, using physics principles. For example, "An increase in temperature provides energy to release more charge carriers in the semiconductor material, increasing conductivity and therefore decreasing its resistance."
Do I need to write in full sentences for 'State' or 'List' questions?
Not necessarily. For State, a concise phrase or even a single value is usually sufficient. For List, using clear bullet points is often better than writing a long paragraph, as it makes your points distinct for the examiner. The key is precision, not prose. You can see how this works in practice if you try to mark a paper against a real mark scheme.