📚 AQA 9630 International A Level Physics Command Words | AQA 9630 国际 A Level 物理指令词
Command words are the verbs at the start of AQA International A Level Physics (9630) questions. They tell you how much to write and which skills to show. For example, 'state' asks for a short factual answer, while 'explain' requires a logical chain of physics. Many students know the physics but lose marks because they answer the wrong command word. This guide explains the main command words, what examiners expect, and how to tailor your answer to the mark scheme.
指令词是 AQA 国际 A Level 物理（9630）题目开头的动词。它们告诉你需要写多少内容以及展示什么技能。例如 "state" 只要求简短的事实答案，而 "explain" 要求一条逻辑清晰的物理推理链。很多学生懂物理知识，却因为答错了指令词而丢分。本指南讲解主要指令词、考官期望，以及如何让答案与评分方案匹配。
1. Why Command Words Decide Your Grade | 为什么指令词决定你的等级
AQA splits assessment into AO1 (knowledge and recall), AO2 (application of knowledge) and AO3 (analysis, evaluation and judgement). Command words signal the targeted objective. State and define usually test AO1; calculate and determine test AO2; evaluate and discuss test AO3. Before writing, circle the command word and think: is this recall, calculation, or judgement? Matching answer depth to the command word prevents over-writing and under-writing.
AQA 将评估分为 AO1（知识与记忆）、AO2（知识应用）和 AO3（分析、评价与判断）。指令词能提示考查目标。State 和 define 通常考查 AO1；calculate 和 determine 考查 AO2；evaluate 和 discuss 考查 AO3。动笔前圈出指令词，想一想：这是记忆、计算还是判断？让答案深度与指令词匹配，可以避免写得过多或过少。
- AO1: state, define, give, name, list - short factual recall.
AO1：state、define、give、name、list——简短的事实回忆。 - AO2: calculate, determine, show that, estimate, deduce - apply physics to data or a situation.
AO2：calculate、determine、show that、estimate、deduce——把物理应用到数据或情境中。 - AO3: explain, discuss, evaluate, justify, compare - build reasoning, weigh evidence and judge.
AO3：explain、discuss、evaluate、justify、compare——建立推理、权衡证据并作出判断。
Examiners write mark schemes around command words. A 'state' mark point is often one short phrase; an 'explain' mark point is a causal step. If you write a long paragraph for 'state', you waste time. If you write one word for 'explain', you cannot access the reasoning marks.
考官围绕指令词编写评分方案。"state" 的得分点通常是一个短句；"explain" 的得分点是一个因果步骤。如果你对 "state" 写一大段，就是浪费时间；如果你对 "explain" 只写一个词，就拿不到推理分。
2. How to Read a Command Word Before You Write | 动笔前如何拆解指令词
Use a three-part reading method. First, underline the command word. Second, identify the physics content it refers to. Third, note limiting words such as 'in terms of', 'using the graph', 'hence' or 'to two significant figures'. These limiting words decide what counts as a valid answer.
使用三步阅读法。第一，划出指令词。第二，确定它指向的物理内容。第三，注意限制词，例如 "in terms of"、"using the graph"、"hence" 或 "to two significant figures"。这些限制词决定什么答案才算有效。
- Step 1: Circle the command word and decide AO1, AO2 or AO3.
第一步：圈出指令词，判断是 AO1、AO2 还是 AO3。 - Step 2: Underline the physics quantity, law or situation being asked about.
第二步：划出被问到的物理量、定律或情境。 - Step 3: Check the marks. One mark usually needs one point; three marks need three linked points; six marks need a structured argument.
第三步：看分值。1 分通常需要 1 个要点；3 分需要 3 个相互关联的要点；6 分需要结构化论证。 - Step 4: Plan for ten seconds before writing. A short plan prevents repetition and omission.
第四步：写前用十秒规划。简短计划可以防止重复和遗漏。
Do not begin with a formula unless the command word asks for calculation or derivation. For 'explain', begin with the physics cause. For 'evaluate', begin by identifying the criteria you will judge against.
除非指令词要求计算或推导，否则不要一上来就写公式。对于 "explain"，从物理原因开始；对于 "evaluate"，先说明你将依据什么标准来评价。
3. AO1 Command Words: State, Define, Give, Name, List | AO1 指令词：State、Define、Give、Name、List
'State' asks for a short factual answer with no explanation. 'Define' asks for a precise meaning, often using a defining equation or a word definition with the correct per unit phrase. 'Give' asks for one example, value or reason. 'Name' asks for a specific term, unit or particle. 'List' asks for several separate points without development.
"State" 要求简短的事实答案，不需要解释。"Define" 要求精确含义，通常使用定义式或包含正确 "每单位" 表述的文字定义。"Give" 要求一个例子、数值或理由。"Name" 要求一个具体术语、单位或粒子。"List" 要求若干独立要点，不需要展开。
- State the SI unit of magnetic flux density. Answer: tesla (T).
State 磁感应强度的国际单位。答案：特斯拉（T）。 - Define electric field strength. Answer: force per unit positive charge.
Define 电场强度。答案：单位正电荷所受的力。 - Give one example of a transverse wave. Answer: light or any electromagnetic wave.
Give 一个横波的例子。答案：光或任何电磁波。 - Name the particle exchanged in the strong interaction. Answer: gluon.
Name 强相互作用中交换的粒子。答案：胶子。
For 'define', avoid vague words such as 'amount' or 'strength' unless they are part of the accepted definition. For example, gravitational potential is 'work done per unit mass in bringing a small test mass from infinity to the point'. The phrase 'per unit mass' and 'from infinity' are both mark points.
对于 "define"，避免使用 "amount" 或 "strength" 这类模糊词，除非它们是标准定义的一部分。例如引力势是 "把单位质量的小测试质量从无穷远处移到该点所做的功"。"per unit mass" 和 "from infinity" 都是得分点。
4. AO2 Command Words: Calculate, Determine, Show That, Estimate, Deduce | AO2 指令词：Calculate、Determine、Show That、Estimate、Deduce
'Calculate' requires a numerical answer from given data. Always write the equation, substitute values with units, then give the answer with a unit and sensible significant figures. 'Determine' may require reading a graph, finding a gradient, or combining two physical relationships. 'Show that' requires you to prove a printed value; you must start from the correct equation and show every substitution step until you reach the given answer.
"Calculate" 要求用给定数据算出数值答案。一定要写方程、代入带单位的数值，然后给出带单位和合理有效数字的答案。"Determine" 可能需要读图、求斜率，或组合两个物理关系。"Show that" 要求证明题目中已给出的数值；你必须从正确方程出发，展示每一步代入，直到得到该给定值。
v = f λ
Eₖ = ½ m v²
F = B I L sin θ
'Estimate' asks for an approximate value based on known physics and reasonable assumptions. State your assumed values clearly. 'Deduce' asks you to reach a conclusion from a physics principle or from data, often without a full calculation. For example, deduce the direction of an induced current using Lenz's law.
"Estimate" 要求基于已知物理和合理假设给出近似值。清楚写出你假设的数值。"Deduce" 要求你根据物理原理或数据得出结论，通常不需要完整计算。例如，用楞次定律推断感应电流方向。
- Calculate: equation → substitution → answer + unit.
Calculate：方程 → 代入 → 答案 + 单位。 - Show that: start from the equation, substitute given values, end with the printed value. Do not use the printed value as a starting number.
Show that：从方程开始，代入给定值，最后得到题目印出的数值。不要把印出的数值当作起始数字。 - Determine: may need graph gradient, area under graph, or two equations combined.
Determine：可能需要图线斜率、图线下面积，或组合两个方程。 - Estimate: state assumptions, use order-of-magnitude values, keep units.
Estimate：写出假设，使用数量级数值，保留单位。
5. Explain and Describe: The Two Most Confused Words | Explain 与 Describe：最易混淆的两个词
'Describe' asks what happens, what is observed, or what the graph shows. 'Explain' asks why it happens. A description can be a sequence of observations; an explanation must include a causal chain with words such as 'because', 'so', 'therefore' or 'this causes'. Each valid causal link can earn a mark.
"Describe" 要求说明发生了什么、观察到什么，或图像显示了什么。"Explain" 要求说明为什么发生。描述可以是观察到的现象序列；解释必须包含因果链，使用 "because"、"so"、"therefore" 或 "this causes" 等词。每一个有效的因果环节都可以得分。
| Command word | What to write | Physics example |
| Describe | What is observed or what happens | The resistance of the thermistor decreases as temperature increases. |
| Explain | Why it happens, with causal links | Temperature increases, so more charge carriers are released, so resistance decreases. |
a physical process unless you state what each quantity does and why. For example, writing 'R = V / I' does not explain why resistance changes; you must explain the microscopic behaviour.
一个常见错误是把公式当作解释。除非你说明每个量如何变化以及为什么，公式本身不能解释物理过程。例如，写 "R = V / I" 不能解释电阻为什么变化；你必须解释微观行为。
6. Command Words for Data, Graphs and Practical Skills | 数据、图像与实验技能指令词
Practical and data questions use words such as plot, draw, sketch, measure, record, read off, determine the gradient, describe the relationship, suggest, and identify. Each has a precise expectation. 'Plot' means mark the points accurately. 'Draw' usually means draw a line or diagram. 'Sketch' means show the correct shape and key features without plotting every point.
实验与数据题使用 plot、draw、sketch、measure、record、read off、determine the gradient、describe the relationship、suggest、identify 等词。每个词都有精确要求。"Plot" 指准确标出数据点。"Draw" 通常指画线或示意图。"Sketch" 指画出正确形状和关键特征，不必逐点描画。
- Measure: state the instrument and the quantity, for example measure current with an ammeter in series.
Measure：说明仪器和物理量，例如用串联电流表测量电流。 - Record: present readings in a table with units in the header.
Record：把读数记录在表格中，单位写在表头。 - Read off: use the graph scale carefully and give the value with a unit.
Read off：仔细使用图线刻度，给出带单位的值。 - Determine the gradient: choose a large triangle on the line of best fit, not on data points.
Determine the gradient：在最佳拟合线上选一个大三角形，不要用数据点。 - Describe the relationship: state proportionality, linearity, or trend, including what happens at the origin.
Describe the relationship：说明正比、线性或趋势，包括原点处的行为。
ding uncertainty is ± half the smallest division. Percentage uncertainty is calculated as:
对于不确定度，仪器的分辨率是它能检测到的最小变化。典型的读数不确定度是 ± 最小分度的一半。百分比不确定度计算为：
percentage uncertainty = (Δx ÷ x) × 100%
When you 'suggest' a practical improvement, link it to the specific error. For example, 'use a wider range of values to reduce the percentage uncertainty in the gradient' is better than 'be more careful'.
当你 "suggest" 实验改进时，要把它与具体误差联系起来。例如，"使用更宽范围的数值以减小斜率的百分比不确定度" 比 "更小心一点" 更好。
7. Compare, Contrast, Discuss, Evaluate: AO3 Command Words | Compare、Contrast、Discuss、Evaluate：AO3 指令词
AO3 command words carry the highest tariff and require judgement. 'Compare' requires both similarities and differences. 'Contrast' requires differences only. 'Discuss' requires a balanced argument with evidence on both sides. 'Evaluate' requires a judgement or conclusion after weighing strengths and limitations.
AO3 指令词分值最高，要求判断。"Compare" 要求相同点和不同点。"Contrast" 只要求不同点。"Discuss" 要求平衡论证，双方都有证据。"Evaluate" 要求权衡优缺点后给出判断或结论。
- Compare: both A and B have the same unit, but A is a vector and B is a scalar.
Compare：A 和 B 单位相同，但 A 是矢量而 B 是标量。 - Contrast: A decreases with distance, whereas B increases with distance.
Contrast：A 随距离减小，而 B 随距离增大。 - Discuss: one advantage is... however, a disadvantage is... therefore the overall effect depends on...
Discuss：一个优点是……然而，一个缺点是……因此总体效果取决于…… - Evaluate: the model is useful because... but it is limited because... overall it is valid within...
Evaluate：该模型有用，因为……但它有局限，因为……总体而言，它在……范围内有效。
For 'evaluate', use data from the question. A judgement without evidence cannot reach the top band. If the question asks 'evaluate whether the student's conclusion is valid', you must refer to the actual values, uncertainties or assumptions given.
对于 "evaluate"，要使用题目中的数据。没有证据的判断无法进入最高档。如果题目问 "evaluate whether the student's conclusion is valid"，你必须引用题目给出的实际数值、不确定度或假设。
8. Justify, Comment, Suggest and Outline: Precision in Short Answers | Justify、Comment、Suggest 与 Outline：短答案中的精确性
'Justify' means give a reason based on physics. It is stronger than 'explain' in the sense that you must show why your choice or method is correct. 'Comment' asks for a short evaluative point, often about a trend, a limitation or a trade-off. 'Suggest' is used in unfamiliar contexts; you must apply known physics rather than recall a standard answer. 'Outline' asks for the main steps or features without detail.
"Justify" 指给出基于物理的理由。它比 "explain" 更强，因为你必须说明你的选择或方法为什么正确。"Comment" 要求简短的评述，通常关于趋势、局限或权衡。"Suggest" 用于不熟悉的情境；你必须应用已知物理，而不是回忆标准答案。"Outline" 要求主要步骤或特征，不需要细节。
- Justify: the acceleration is zero because the resultant force is zero; therefore velocity is constant.
Justify：加速度为零，因为合力为零；因此速度恒定。 - Comment: the efficiency increases at first, but above 60 °C the losses become dominant.
Comment：效率起初上升，但高于 60 °C 后损耗占主导。 - Suggest: in a new context, use conservation of energy or momentum to predict the outcome.
Suggest：在新情境中，用能量守恒或动量守恒预测结果。 - Outline: list the key stages, for example 'switch on, adjust, record, repeat'.
Outline：列出关键阶段，例如 "打开、调节、记录、重复"。
Short command words often appear in multi-part questions. If part (a) says 'state' and part (b) says 'hence calculate', part (b) depends on part (a). You must use your previous answer or the given value, and the word 'hence' means you should not start from first principles unless necessary.
短指令词常出现在多部分题目中。如果 (a) 说 "state"，(b) 说 "hence calculate"，那么 (b) 依赖 (a)。你必须使用前一问答案或给定值；"hence" 意味着除非必要，否则不要从第一性原理重新开始。
9. Physics Examples: Matching Command Words to Topics | 物理实例：指令词与考点匹配
Command words appear across all 9630 topics: mechanics, materials, waves, electricity, thermal physics, fields, nuclear physics and optional units. The physics changes, but the command word expectation stays the same. The table below shows how the same command word works in different topics.
指令词出现在 9630 所有主题中：力学、材料、波、电学、热学、场、核物理和选修单元。物理内容会变，但指令词的要求不变。下表展示同一指令词在不同主题中的用法。
| Topic | Command word | Expected answer type |
| Mechanics | Calculate | Use s = u t + ½ a t² or v² = u² + 2 a s, substitute and give unit. |
| Mechanics | Explain | Explain terminal velocity: weight = drag, resultant force zero, acceleration zero. |
| Electricity | Determine | Find resistance from the gradient of a V-I graph. |
| Waves | Describe | Describe the diffraction pattern: central maximum, side maxima, decreasing intensity. |
| Thermal physics | Estimate | Estimate energy using ΔQ = m c Δθ with assumed mass and temperature change. |
| Nuclear physics | Discuss | Discuss binding energy per nucleon: fusion and fission both increase it, releasing energy. |
If a question uses a context you have not seen, do not panic. Replace the unfamiliar object with a familiar physics model: a spring, a resistor, a capacitor, a wave or a particle
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