📚 IGCSE Physics Exam Technique Guide | IGCSE物理试题高分技巧详解
The IGCSE Physics examination (e.g. Cambridge IGCSE 0625) tests more than just your knowledge of formulas and definitions. It tests your ability to apply that knowledge under timed conditions, interpret questions precisely, and communicate answers in the way examiners expect. This guide breaks down the essential techniques that turn a good physics student into a high-scoring candidate.
IGCSE 物理考试（如剑桥 IGCSE 0625）考查的不仅仅是你对公式和定义的记忆，更考查你在限定时间内运用知识的能力、准确理解题意的能力，以及按照考官期待的方式组织答案的能力。本指南将解析这些关键技巧，帮助你从"物理学得不错"提升为"考试拿高分"。
1. Understand the Command Words | 读懂指令词
Every question begins with a command word that tells you exactly what the examiner expects. For example, "state" and "name" require a single, brief fact with no explanation. "Define" requires a formal definition, often memorised word-for-word. "Explain" requires a reason or mechanism, and usually earns marks for linking cause and effect. "Calculate" expects a numerical answer with working shown, while "Describe" may require both a written account and a graphical element.
每道题的开头都有一个指令词，它精确地告诉你在答什么。"State" 和 "name" 只需要简要写一个事实，不需要解释；"Define" 需要正式的定义，通常要逐字背下来；"Explain" 需要说明原因或机制，通常因为建立了因果关系而得分；"Calculate" 需要计算结果并展示步骤；"Describe" 可能既需要文字描述，也需要画图。
Misreading the command word is the most common cause of lost marks. If the question asks you to "suggest", there is no single correct answer — you need to offer a plausible idea even if it is not taught in the syllabus. If it asks you to "compare", you must mention both similarities and differences; stating only one side loses marks.
误读指令词是失分最常见的原因。如果题目要求你"suggest"（提出建议），这就没有唯一正确答案——你需要给出一个合理的想法，即使大纲没有直接讲过。如果题目要求你"compare"（比较），你必须同时提到相同点和不同点；只写一边会丢分。
2. Know Your Definitions Word for Word | 逐字掌握定义题
IGCSE physics papers regularly open with a definition question worth 1–3 marks. Common ones include: "Define speed", "Define acceleration", "Define density", "Define pressure", "Define work done", "Define power", and "Define specific heat capacity". These are easy marks if you know the exact wording expected by the examiner.
IGCSE 物理试卷经常以定义题开场，占 1–3 分。常见的定义题包括：速度、加速度、密度、压强、做功、功率和比热容。如果你知道考官期望的准确措辞，这些就是送分题。
Take care with definitions that include conditions. For example: "Power is the rate of work done" is correct, but you must not say "rate of energy transfer" for efficiency unless you mention useful energy. Similarly, "specific latent heat is the energy required to change the state of 1 kg of a substance without a change in temperature" — the phrase "without a change in temperature" is essential for the mark.
注意包含条件的定义。例如"功率是做功的速率"是正确的，但不能把效率说成"能量转移的速率"而不提有用能量。类似地，"比潜热是使 1 kg 物质改变状态且温度不变所需的能量"——"温度不变"这一短语是得分关键。
| Frequent definition question | Exam-accepted wording |
| Define acceleration | The rate of change of velocity (in a unit time). |
| Define density | The mass per unit volume. |
| Define pressure | The normal force per unit area. |
| Define work done | The product of force and distance moved in the direction of the force. |
Memorise these as complete phrases. Partial answers such as "force on an area" for pressure usually lose the mark because "per unit area" is missing.
要记住完整的短语。像"压强就是作用在面积上的力"这类不完整的回答通常会丢分，因为缺少"单位面积"。
3. Show Every Step in Calculations | 计算题必须写出每一个步骤
In any calculation question, you are awarded marks for three distinct things: the correct method, the correct substitution, and the correct answer. Even if your final answer is wrong, you can still gain marks from your working. This means you should always write down the formula, substitute in the numbers, and only then perform the arithmetic.
在任何计算题中，你因三件事分别得分：正确的方法、正确的代入、正确的答案。即使最终答案错了，你仍然可以从步骤中获得分数。因此你必须先写出公式，然后代入数字，最后才做算术。
Consider the example: "A car accelerates from 2 m/s to 10 m/s in 4 s. Calculate the acceleration." A full working is:
例如这道题："一辆汽车在 4 秒内从 2 m/s 加速到 10 m/s。计算加速度。"完整的步骤是：
a = (v - u) / t = (10 - 2) / 4 = 2 m/s²
Each part above earns a mark in many mark schemes: the formula, the substitution, and the answer. Never write just the final number — you lose method marks if the number is wrong, and even if it is right, the examiner may suspect you guessed.
上面的每一步在评分方案中都可能得到一分：公式、代入、答案。永远不要只写最终数字——如果数字错了，你会丢掉步骤分；即使数字对了，考官也可能怀疑你是猜的。
Always include units in your final answer. If you forget to write "m/s²" where it is required, you lose the final answer mark. Check whether the question tells you the expected unit: if it says "Give your answer in m/s", do not leave your answer in km/h.
在最终答案中一定要带单位。如果需要在答案中写"m/s²"而你没有写，就会丢掉最终答案的分。注意题目是否告诉你期望的单位：如果它说"以 m/s 为单位给出答案"，就不要写成 km/h。
4. Master Unit Conversions Before the Exam | 考前攻克单位换算
Many marks are lost because candidates slip up on unit conversions. The most common conversions in IGCSE physics are: km to m (multiply by 1000), cm to m (divide by 100), mm to m (divide by 1000), minutes to seconds (multiply by 60), hours to seconds (multiply by 3600), g to kg (divide by 1000), and cm² to m² (divide by 10 000), cm³ to m³ (divide by 1 000 000).
许多分数因为单位换算失误而丢失。IGCSE 物理中最常见的换算包括：km 转 m（乘 1000），cm 转 m（除以 100），mm 转 m（除以 1000），分钟转秒（乘 60），小时转秒（乘 3600），g 转 kg（除以 1000），cm² 转 m²（除以 10 000），cm³ 转 m³（除以 1 000 000）。
Speed and density calculations fail most often because of area and volume conversions. For example, if pressure is given in N/cm² and you need it in N/m², multiply by 10 000. If density is given in g/cm³ and you need it in kg/m³, multiply by 1000. Write your conversion step out on the answer line so that the examiner can see it — if you make an error early, you may still gain a method mark.
速度和密度计算最容易因为面积、体积换算而出错。例如，如果压强以 N/cm² 给出，而你需要 N/m²，就乘 10 000。如果密度以 g/cm³ 给出，你需要 kg/m³，就乘 1000。把换算步骤写在答题线上，这样考官可以看到——即使前面出错，你也可能得到步骤分。
5. Pay Attention to Significant Figures | 重视有效数字
IGCSE physics examiners expect your final answer to be given to the same or a slightly higher number of significant figures as the data in the question. If the question provides values like 4.0 m and 2.0 s, your answer should normally be given to 2 significant figures. An answer stated as "2.0 m/s" is safer than "2 m/s" when the data given includes a zero after the decimal point.
IGCSE 物理考官期望你的最终答案与题目数据保持一致的有效数字位数，或者略多。如果题目给的是 4.0 m 和 2.0 s 这样的数值，你的答案通常应该保留 2 位有效数字。写"2.0 m/s"比写"2 m/s"更稳妥，因为给出的数据在小数点后有一个零。
If the question does not specify significant figures, use the general rule: give your answer to 2 or 3 significant figures, or the same as the data. Giving more digits than necessary is not penalised heavily, but giving far too few — for example answering "0.1" when the calculated value is 0.1264 — may lose the final mark.
如果题目没有指定有效数字，就用通用规则：保留 2 或 3 位有效数字，或与数据一致。多余的必要位数扣分不重，但如果位数太少——比如算出来是 0.1264 却回答"0.1"——就可能丢掉最终答案分。
6. Draw and Read Graphs Accurately | 正确作图与读图
Graph questions appear in almost every IGCSE physics paper. For plotting graphs, always use sharp pencil, check that each axis has the correct variable drawn on the correct axis (independent on x, dependent on y), and include the unit in brackets on each axis label. Plot each point with a small neat cross rather than a dot, because a dot has a thick uneven shape that is hard to locate precisely.
几乎每份 IGCSE 物理试卷都有作图题。画图时要用削尖的铅笔，确保每个坐标轴正确标注变量（自变量在 x 轴，因变量在 y 轴），轴标签中要用括号写出单位。用一个小而整齐的×来标点，而不是用圆点，因为圆点又粗又不规则，难以精确定位。
For lines of best fit, use a thin transparent ruler, draw a straight line or a smooth curve that balances the points, and do not force the line through the origin unless the question tells you it passes through (0,0). Many candidates lose marks by drawing a thick, wobbly line or connecting dot-to-dot instead of drawing the line of best fit.
画最佳拟合线时，用透明的细直尺，画一条能平衡各点的直线或平滑曲线，不要强迫直线通过原点，除非题目告诉你它经过(0,0)。许多考生因为画出又粗又抖的线，或者点对点连线而不是画最佳拟合线而失分。
For reading graphs, use the line, not the data points, to interpolate. When calculating a gradient, choose two points that are far apart on the line (not data points, and not the centroid), read their coordinates as precisely as possible, and show the gradient calculation clearly:
读图时，用线来插值，而不是用原始数据点。计算斜率时，在线上选择两个相距较远的点（不是数据点，也不是整组点的中心点），尽可能精确地读取坐标，并清晰地列出斜率计算：
gradient = (y₂ - y₁) / (x₂ - x₁)
Include the correct units in your gradient answer, since the gradient often represents a physical quantity, such as the speed on a distance-time graph.
在斜率答案中写清楚单位，因为斜率通常代表一个物理量，比如位移-时间图像上的速度。
7. Handle Units and Prefixes in Data | 处理数据中的单位与词头
IGCSE physics makes heavy use of metric prefixes: k (kilo, 10³), c (centi, 10⁻²), m (milli, 10⁻³), and sometimes M (mega, 10⁶). You must convert to base units before substituting into formulas. Writing 2 kJ as 2000 J, or 5 cm as 0.05 m, is a required step, not an optional one.
IGCSE 物理大量使用十进制词头：k（千，10³）、c（厘，10⁻²）、m（毫，10⁻³），有时还有 M（兆，10⁶）。在代入公式前必须换算成基本单位。把 2 kJ 写成 2000 J，或把 5 cm 写成 0.05 m，是必须完成的步骤，而不是可选项。
A common mistake is mixing cm with m inside the same formula. If you are calculating pressure using force in N and area in cm², you must convert the area to m² first. Writing the unit conversion explicitly in your working helps you avoid hidden errors.
一个常见错误是在同一公式中混用 cm 和 m。如果你用 N 为单位的力和 cm² 为单位的面积计算压强，必须先把面积换算成 m²。在步骤中明确写出单位换算，有助于避免隐藏的错误。
8. Answer "Explain" Questions with a Cause-and-Effect Link | 用因果链回答"解释"题
"Explain" questions are the biggest source of lost marks for many IGCSE candidates. To gain full marks, your answer must contain a mechanism, not just a restatement. For example, if asked to explain why a metal feels colder than a wooden block at the same temperature, a weak answer says "because metal is colder" — which earns zero. A strong answer says: "Metal is a better conductor of heat than wood. Heat flows from your hand into the metal at a higher rate, so the skin cools faster, making it feel colder."
"解释"题是许多 IGCSE 考生丢分的最大来源。要得满分，你的答案必须包含机制，而不是重复题目。例如，如果要求解释为什么金属在同一温度下比木头感觉更冷，弱答案是"因为金属更冷"——得零分。强答案说："金属比木头导热更好。热从手流向金属的速率更高，皮肤降温更快，所以感觉更冷。"
Use the words "because", "so", "therefore" to make the chain of reasoning explicit. Aim for two or three linked sentences. An answer with two separate, correct but unlinked points often earns fewer marks than a shorter answer with one complete causal chain.
使用"因为""所以""因此"等词来明确推理链条。目标写两三句有联系的话。一个包含两点正确但互不关联的答案，往往不如一个具有完整因果链的简短答案得分高。
9. Lab-Based Questions: Variables, Tables, and Errors | 实验题：变量、表格与误差
IGCSE physics paper 5/6 tests practical skills. Questions often ask for the independent variable, the dependent variable, and the control variables. The independent variable is the one that you deliberately change; the dependent variable is the one you measure; control variables must be kept constant for a fair test.
IGCSE 物理卷 5/6 考查实验技能。题目常问自变量、因变量和控制变量。自变量是你有意改变的变量；因变量是你测量的变量；控制变量必须保持不变才能保证公平测试。
When asked to plan an experiment, mention the apparatus, the measurements, and how you will ensure safety. If asked to describe how to improve accuracy, mention repeating readings and calculating a mean, using a device with finer resolution (e.g. a digital stopwatch instead of a manual one), and checking for zero error.
当要求设计实验时，要提到器材、测量方法以及如何保证安全。如果要求描述如何提高精确度，可以提到重复读数并计算平均值、使用分辨率更高的仪器（例如数字秒表而不是手动秒表），以及检查零误差。
For tables, use the columns for the independent variable and the dependent variable, write the correct unit in the header, and record each reading to a consistent number of decimal places. Do not record a reading that is more precise than the instrument allows, e.g. a time of 15.327 s from a stopwatch that only reads to 0.1 s.
设计表格时，用一列写自变量，一列写因变量，表头写清单位，每个读数保留一致的小数位。不要记录仪器无法达到的精度，比如秒表只能读到 0.1 秒，却记录 15.327 秒。
10. Use Units and the Equation List Wisely | 善用单位与公式表
Most IGCSE physics papers provide an equation list at the front of the paper. You are expected to know which formula to apply, not to copy the whole list. In the exam, identify the key symbols in the question, decide which formula contains those symbols, and write it down as the first line of your working.
大多数 IGCSE 物理试卷在卷首提供公式表。你需要知道用哪个公式，而不是抄整个表。考试时，先找出题目中的关键符号，判断哪个公式包含这些符号，然后把它作为计算步骤的第一行写下来。
Units are a powerful shortcut: if a question asks for "energy in joules", and your calculation involves mass, specific heat capacity, and temperature change, then the formula that connects these three to energy is ΔE = m c Δθ. Checking units helps you pick the right formula and catch mistakes.
单位是一个强大的捷径：如果题目问"以焦耳为单位的能量"，而你的计算涉及质量、比热容和温度变化，那么将这三者与能量联系起来的公式就是 ΔE = m c Δθ。检查单位可以帮助你选择正确的公式并发现错误。
11. Time Management and Paper Strategy | 时间管理与试卷策略
IGCSE physics papers usually allow around 1.5 minutes per mark. For a 2-mark question, plan to spend no more than 3 minutes. Before you start, do a quick scan of the whole paper. Answer the questions you are confident about first; this secures marks and builds momentum. Leave difficult questions for later, but write something for every question — even a formula or a partial explanation may earn marks.
IGCSE 物理试卷通常每分约 1.5 分钟。对于 2 分题，计划不超过 3 分钟。开始前快速浏览整张试卷。先回答有把握的题目，这样能确保得分并建立节奏。难题留到后面，但每道题都要写一些内容——即使一个公式或部分解释也可能得分。
If a calculation seems impossible, write the formula that you believe is relevant. Many mark schemes award one mark for the formula and one for the correct substitution, even when the final answer is missing. Leave 5 minutes at the end to check that all units are correct, all answers are rounded appropriately, and no page has been overlooked.
如果某一计算似乎做不出来，写下你认为相关的公式。许多评分方案会给公式 1 分、正确代入 1 分，即使最终答案缺失。最后留 5 分钟检查所有单位是否正确、答案的约分是否恰当、有没有漏页。
12. Learn From Past Papers and the Mark Scheme | 从真题和评分方案中学习
The quickest way to raise your score is to practise with past papers and compare your answers with the published mark scheme. The mark scheme is not just a list of correct answers; it shows the acceptable alternatives and the exact wording that earns the mark. When you find a definition or explanation wording that differs from yours, adjust your future answers to match the mark scheme.
提高分数最快的方法是用真题练习，并将答案与官方评分方案对照。评分方案不仅仅是正确答案列表，它显示了可接受的替代表述以及得分的准确措辞。当你发现自己的定义或解释措辞与它不同时，请调整以后的答案以匹配评分方案。
As you practise, keep an error log. Write down each mistake you make, the reason for the mistake, and the correct technique. Review this log before each mock exam. Common mistakes such as forgetting to convert units, misreading the instruction word, or writing the dependent variable on the x-axis will disappear quickly if you track them consistently.
练习时，建立一个错误日志。记录你犯的每一个错误、错误原因和正确的技巧。每次模拟考试前复习这份日志。像忘记换算单位、误读指令词、把因变量画在 x 轴上这样常见的错误，只要你坚持记录，就能很快消除。
Published by TutorHao | Physics Revision Series | aleveler.com
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