📚 Year 7 CAIE Physics: Exam Techniques and Marking Criteria | Year 7 CAIE 物理：答题技巧与评分标准
Doing well in Year 7 CAIE Physics is about more than just remembering facts. You need to understand exactly what the question is asking, present your answers in a clear and structured way, and know how examiners award marks. This guide will walk you through the essential exam techniques, from interpreting command words and handling units to structuring calculations and designing experiments. You will also learn how marks are typically allocated, so you can maximise your score in every question.
在 Year 7 CAIE 物理考试中取得好成绩，不仅需要记住知识点，更要准确理解题目要求，用清晰有条理的方式呈现答案，并了解评分者如何给分。本指南将带领你掌握关键的答题技巧，包括解读指令词、处理单位、构建计算过程、设计实验等。同时，你还会了解分数分配的一般规则，从而在每道题中争取最高分。
1. Understanding Command Words | 理解指令词
Command words tell you the type of answer that is expected. In CAIE physics exams, words such as 'state', 'describe', 'explain', and 'calculate' are used very precisely.
指令词告诉你题目要求的是哪种答案。在 CAIE 物理考试中，“state”、“describe”、“explain”和“calculate”等词语的使用非常精确。
'State' means give a short, factual answer. Often it is just a name, a unit, or a single sentence. For example, 'State the unit of force.' – your answer should simply be 'newton'.
'State' 表示给出一个简短、事实性的答案，通常只是一个名称、一个单位或一个单句。例如，“State the unit of force.”——你的答案只需是“newton”。
'Describe' asks you to say what happens in detail. You do not need to explain why. For instance, 'Describe how the speed of the ball changes as it falls.' – you would say 'The speed increases as the ball falls downwards.'
'Describe' 要求你详细说明发生了什么，不需要解释原因。例如，“Describe how the speed of the ball changes as it falls.”——你应该回答“球下落时速度增加”。
'Explain' requires you to give reasons using scientific ideas. You need to link cause and effect. For example, 'Explain why a parachutist slows down when the parachute opens.' – you should refer to the increase in air resistance and unbalanced forces.
'Explain' 要求你利用科学概念给出原因，需要将因果联系起来。例如，“Explain why a parachutist slows down when the parachute opens.”——你应该提到空气阻力增加以及非平衡力的作用。
'Calculate' means you must show your working, use a formula, and include the correct unit in your final answer. Always set out your steps clearly.
'Calculate' 意味着你必须展示计算过程，使用公式，并在最终答案中给出正确的单位。务必清晰列出每一个步骤。
2. Using Correct Units | 使用正确的单位
Units are a key part of any physics answer and are often worth a mark in themselves. The SI system is used: distance in metres (m), time in seconds (s), mass in kilograms (kg), force in newtons (N), speed in metres per second (m/s).
单位是物理答案的重要组成部分，通常本身就是一个得分点。考试采用国际单位制：距离用米（m），时间用秒（s），质量用千克（kg），力用牛顿（N），速度用米每秒（m/s）。
If you are asked to calculate speed, writing '5' is insufficient; you must write '5 m/s'. Similarly, a mass should be written as '2.5 kg', not just '2.5'.
如果要求计算速度，只写“5”是不够的，必须写成“5 m/s”。同样，质量应写为“2.5 kg”，而不是仅写“2.5”。
In questions involving graphs you must label axes with the quantity and its unit, for example 'Time (s)' or 'Distance (m)'. Without units on axis labels, you can lose marks even if the graph plot is perfect.
在涉及图表的问题中，必须为坐标轴标注物理量和单位，比如“Time (s)”或“Distance (m)”。如果坐标轴缺少单位，即使图形绘制得再完美，也会丢分。
ample, 1 km = 1000 m, 1 hour = 3600 s. Be ready to convert km/h to m/s by dividing by 3.6.
在进行单位换算时，务必反复核对十的幂次。例如，1 km = 1000 m，1 小时 = 3600 秒。准备好将 km/h 转换为 m/s 时除以 3.6。
3. Drawing and Labelling Diagrams | 绘制并标注图表
Physics diagrams must be neat, accurate, and fully labelled. Use a sharp pencil and a ruler for straight lines; do not use freehand unless the question asks for a sketch.
物理图表必须整洁、准确且标注完整。使用削尖的铅笔和直尺画直线；除非题目要求画草图，否则不要徒手绘制。
When drawing circuit diagrams, use standard symbols for cells, bulbs, switches, and resistors. Make sure lines are straight and corners are right angles. Join components without gaps.
绘制电路图时，应为电池、灯泡、开关和电阻器使用标准符号。确保线条笔直，转角成直角，元件之间连接紧密无间隙。
Force diagrams (free body diagrams) must show arrows that start from the object, with arrow lengths roughly proportional to force magnitudes. Label each force, e.g. 'weight', 'pull', 'upthrust'.
力图（自由体图）必须从物体出发画箭头，箭头长度大致与力的大小成比例。标注每一个力，例如“weight”（重力）、“pull”（拉力）、“upthrust”（上冲力）。
Marks are awarded for: correct symbols, complete circuit loops, clear labels, and direction of force arrows. Small unnecessary decorations are discouraged as they may look like mistakes.
评分点包括：正确的符号、完整的电路回路、清晰的标注以及力的方向箭头。不建议画无关的装饰，因为它们可能被看作错误。
4. Describing Trends and Patterns | 描述趋势和模式
Many exam questions ask you to describe the trend shown in a table or graph. Use comparative language and refer to both variables. Start by saying what happens overall, then mention any turning points.
许多考题要求你描述表格或图表所呈现的趋势。使用对比性语言，并同时提及两个变量。先总体说明变化情况，然后再指出任何转折点。
For example, 'As time increases, the temperature rises steadily until it reaches 80°C, then remains constant.' This answer clearly links the independent variable (time) to the dependent variable (temperature).
例如，“随着时间增加，温度稳步上升，直到达到80°C，然后保持不变。”这个答案清晰地将自变量（时间）与因变量（温度）联系在一起。
Avoid vague phrases like 'it goes up' or 'it changes'. Be precise: use terms like 'increases linearly', 'decreases at a slower rate', or 'peaks at ...'. If the graph shows two lines, compare them directly, e.g. 'Line A is steeper than line B, showing a faster speed.'
避免使用诸如“它上升了”或“它变化了”这样含糊的表述。要精确：使用“线性增加”、“减速下降”或“在……处达到峰值”等术语。如果图表有两条线，要直接比较它们，例如“线A比线B更陡，表明速度更快”。
5. Calculations and Formula Use | 计算与公式应用
Calculation questions are highly structured and easy to score well on if you follow a routine. The most common formulas for Year 7 are:
计算题的结构性很强，只要按步骤来就很容易拿满分。Year 7 最常用的公式有：
speed = distance ÷ time
density = mass ÷ volume
weight = mass × gravitational field strength (g ≈ 10 N/kg on Earth)
Always start by writing the formula in symbols or words. Then substitute the values (with units), perform the calculation, and finally write the answer with the correct unit. For example:
始终先写出符号公式或文字公式。然后代入数值（带单位），进行计算，最后写出带有正确单位的答案。示例如下：
Question: A car travels 150 m in 5 s. Calculate its speed.
问题：一辆汽车在5秒内行驶了150米。计算它的速度。
Answer: speed = distance ÷ time = 150 m ÷ 5 s = 30 m/s.
答案：速度 = 距离 ÷ 时间 = 150 m ÷ 5 s = 30 m/s。
If the calculation involves changing the subject of the formula, show each algebraic step. Even if your final answer is wrong, you can earn method marks for correct substitution and rearrangement.
如果计算涉及公式变形，要展示每一个代数步骤。即使最终答案错误，只要代入和变形正确，仍能获得方法分。
6. Experimental Design and Variables | 实验设计与变量
When asked to plan an experiment, identify the independent variable (what you change), the dependent variable (what you measure), and at least two control variables (what you keep the same).
当被要求设计实验时，要确定自变量（你改变的物理量）、因变量（你测量的物理量）以及至少两个控制变量（你保持不变的物理量）。
For example, in an investigation on how the length of a pendulum affects its period, the independent variable is pendulum length, the dependent variable is the time for 10 swings, and control variables could be the mass of the bob and the angle of release.
例如，在研究摆长如何影响摆动周期的实验中，自变量是摆长，因变量是10次摆动所用的时间，控制变量可以是摆锤的质量和释放角度。
State clearly how you will change the independent variable (e.g. 'use lengths of 20 cm, 40 cm, 60 cm') and how you will ensure fair testing (e.g. 'use the same stopwatch and start from the same height').
清晰地说明你将如何改变自变量（如“使用20 cm、40 cm、60 cm的长度”），以及如何确保测试公平（如“使用同一块秒表并从同一高度释放”）。
Describe enough practical detail to show you could carry out the experiment. Marks are given for specifying equipment, making repeat measurements, and suggesting a table for results with appropriate headings and units.
描述足够多的操作细节，以证明你能实际完成实验。评分点包括：列出所需器材、进行重复测量，以及建议一个带有合适表头和单位的结果表。
7. Data Presentation: Tables and Graphs | 数据呈现：表格与图表
When constructing a table, place the independent variable in the first column and the dependent variable in the second. Headings must include the quantity and unit separated by a slash or brackets, like 'Length / cm' or 'Time (s)'.
绘制表格时，将自变量放在第一列，因变量放在第二列。表头必须包含物理量和单位，用斜杠或括号分开，如“Length / cm”或“Time (s)”。
For graphs, choose scales that use at least half of the grid space. Label both axes with the variable and unit, and write a clear title. In physics, points are usually plotted as small crosses 'X' and joined with a smooth curve or straight line of best fit.
对于图表，选择的刻度至少要占据一半的网格空间。为两个坐标轴标注变量和单位，并写上清晰的标题。在物理中，描点通常用小叉“X”标记，然后用平滑曲线或最佳拟合直线连接。
Avoid drawing a dot-to-dot line. The line of best fit should follow the general trend of the points, with an even scatter of points on both sides. You may be asked to use the graph to interpolate or extrapolate a value; show this with dotted guide lines.
避免点对点连线。最佳拟合线应当反映点的总体趋势，两侧点的分布大致均匀。你可能会被要求用图表进行内插或外推取值；此时要用虚线作参考线标注。
8. Explaining Scientific Concepts Clearly | 清晰解释科学概念
Examiners expect explanations to use correct scientific vocabulary and logical cause-and-effect chains. Instead of saying 'the stone hits the ground hard', say 'the stone has a greater mass, so its weight is larger, causing a greater impact force when it hits the ground.'
考官期望解释中能使用正确的科学词汇和逻辑清晰的因果链。不应说“石头重重地砸到地上”，而要说“石头的质量更大，因此其重量更大，当它撞击地面时产生了更大的冲击力”。
When explaining phenomena related to forces, energy, or electricity, always refer back to the relevant principle. For example, for sinking and floating, use 'the object sinks because its weight is greater than the upthrust from the water'.
解释与力、能量或电相关的现象时，总要联系到相应的原理。例如，针对沉浮问题，应使用“物体下沉是因为其重量大于水提供的上冲力”。
Connect your sentences with linking words like 'because', 'therefore', 'so', 'as a result', to show the reasoning flow. If a question is worth 2 or 3 marks, make sure your explanation has the same number of distinct science points.
用“because”、“therefore”、“so”、“as a result”等连接词串联句子，以展示推理过程。如果一道题值2分或3分，要确保你的解释中包含相应数量的独立科学要点。
9. Common Mistakes to Avoid | 常见错误避免
One of the most frequent mistakes is forgetting units or using the wrong unit. Always check that the unit matches the quantity: force should be in newtons, not kilograms.
最常见的一个错误是忘记写单位或使用了错误的单位。务必检查单位是否与物理量匹配：力应该用牛顿，而不是千克。
he same everywhere. Weight is a force (measured in N) and depends on gravity. Do not write 'mass = 5 N'.
混淆质量和重量是另一个常见的陷阱。质量是物质的数量（以 kg 为单位），处处相同。重量是力（以 N 为单位），取决于重力。千万不要写出“mass = 5 N”。
In circuit diagrams, students often draw short circuits or forget to place a switch. Check that there is a complete loop from one terminal of the battery to the other. Also, ensure ammeters are placed in series and voltmeters in parallel.
在电路图中，学生常常画出短路或遗忘开关的位置。检查是否存在一条从电池一极到另一极的完整回路。此外，确保电流表串联、电压表并联。
Another error is writing a description when an explanation is asked for, and vice versa. Highlight the command word in the question to keep you focused.
另一个错误是，本题要求解释却写成了描述，反之亦然。将题目中的指令词圈出来，以保持答题方向正确。
10. Marking Criteria: How Marks Are Awarded | 评分标准：分数如何分配
CAIE Physics questions usually have the marks broken down into small, achievable steps. For a 2-mark question, each correct physics point typically earns one mark. For calculation questions, you may get one mark for correct substitution and one for the correct answer with unit.
CAIE 物理题目通常把分数分解为小而可达成的步骤。对于一道2分题，每个正确的物理要点一般得1分。对于计算题，你可能因正确代入得1分，因正确答案及单位得1分。
Below is an example showing how a typical question is marked, so you can see exactly what examiners look for.
下面这个例子展示了一道典型题目是如何评分的，你可以清楚地看到考官在寻找什么。
| Description | English Answer | 中文答案 | Marks |
|---|---|---|---|
| Full-mark answer | The car accelerates more slowly on sand because the sand provides less friction (or grip) for the tyres. With less grip, the engine's force cannot push the car forward as effectively, so the acceleration is smaller. | 汽车在沙地上加速较慢，因为沙地给轮胎提供的摩擦力（或抓地力）较小。抓地力小，发动机的力无法有效推动汽车前进，因此加速度较小。 | 2 / 2 |
| Partial answer | The car is slower on sand because sand is softer. | 汽车在沙地上更慢，因为沙子更软。 | 1 / 2 – identifies a property of sand but does not link to friction or force. |
| Insufficient answer | Because it is sand. | 因为那是沙地。 | 0 / 2 – no scientific reasoning. |
Notice that to obtain full marks, the answer must contain a clear science idea (lower friction) and the link to the effect (reduced acceleration). This structure is typical across explanation questions.
请注意，要获得满分，答案必须包含明确的科学观点（摩擦力较小）及其与结果（加速度减小）的关联。这个结构是解释类题目的典型要求。
11. Time Management and Checking | 时间管理与检查
Allocate your time according to the marks available. If a question is worth 1 mark, spend no more than about 1 minute on it. A 5-mark question may deserve 5–7 minutes. Do not get stuck on one difficult part; move on and return later.
根据分值分配考试时间。如果一道题1分，最多花大约1分钟完成。一道5分的题可以花费5-7分钟。不要在某个难题上卡住，先跳过去，之后回头再做。
Always reserve the last 5 minutes of the exam for checking. Re-read your answers against the question to ensure you have given what was asked. Check calculations, units, graph labels, and spelling of key scientific terms.
始终在考试的最后留出5分钟用于检查。对照题目重新阅读你的答案，确保所答即所问。检查计算过程、单位、图表标签以及关键科学术语的拼写。
When checking, ask yourself: Did I answer the command word correctly? Did I include units? Is my diagram complete? Have I used scientific language appropriately? This final sweep can easily pick up several extra marks.
在检查时，问一问自己：我是否正确回应了指令词？我是否包含了单位？我的图表是否完整？我是否恰当使用了科学语言？这一轮最后的扫视，常常能轻松捞回好几分。
With practice, these techniques will become second nature, and you will walk into your Year 7 CAIE Physics exam well prepared and confident.
通过练习，这些技巧将变成你的第二天性，你会充分准备、满怀信心地走入 Year 7 CAIE 物理考场。
Published by TutorHao | Physics Revision Series | aleveler.com
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