📚 Year 7 WJEC Physics: In-depth Past Paper Analysis | Year 7 WJEC 物理：历年真题深度解析
Past papers are the single most effective revision tool for Year 7 WJEC Physics. They reveal not only what you need to know, but how examiners expect you to show your understanding. This article dissects common question types, highlights tricky areas, and provides step‑by‑step walkthroughs using genuine exam‑style examples.
历年真题是 Year 7 WJEC 物理最有效的复习工具。它们不仅揭示你需要掌握的知识，还展示考官期望你如何表现你的理解。本文剖析常见题型，突出易混淆的领域，并通过真实的考试风格例子提供逐步解析。
1. Command Words: The Key to Marks | 指令词：得分的钥匙
In WJEC papers, command words such as ‘state’, ‘describe’, ‘explain’ and ‘calculate’ guide you on how to structure your answer. ‘State’ often requires a one‑word or short‑phrase answer without reasoning. ‘Describe’ wants you to say what happens or what you see, while ‘explain’ demands a scientific reason.
在 WJEC 试卷中，诸如 ‘state’、‘describe’、‘explain’ 和 ‘calculate’ 这样的指令词指导你如何构建答案。‘State’ 通常要求一个词或简短短语，无需推理。‘Describe’ 要求你说出发生了什么或观察到什么，而 ‘explain’ 则要求给出科学理由。
Example past‑paper question: State the unit of electric current. The answer is simply ampere (amp). A student who writes ‘It is measured in amps and shows how much charge flows’ loses time and may even be marked incorrectly because the command is ‘state’, not ‘explain’.
真题示例：State the unit of electric current. 答案就是 ampere (amp)。如果学生写成 ‘它是用安培测量的，显示电荷流动的多少’，不仅浪费时间，还可能因指令词是 ‘state’ 而非 ‘explain’ 而失分。
Always underline the command word in the question. Then match your answer length and depth: for ‘calculate’ show your working; for ‘name’ or ‘identify’ be precise; for ‘compare’ use comparative words like ‘higher than’ or ‘whereas’.
一定要在题目中划出指令词。然后让你的答案长度和深度与之匹配：‘calculate’ 要显示解题步骤；‘name’ 或 ‘identify’ 要精确；‘compare’ 要使用 ‘higher than’ 或 ‘whereas’ 这样的比较词。
to do: State (single fact) / Describe (detail) / Explain (reason) / Calculate (show maths)
指令词 → 怎么做：State (单一事实) / Describe (细节) / Explain (原因) / Calculate (展示数学步骤)
2. Speed and Motion Calculations | 速度和运动计算
tance ÷ time. Often you will need to rearrange the formula to find distance or time, or convert units before substituting numbers.
速度计算是 Year 7 WJEC 历年真题中的常见题型。你必须熟练运用公式：速度 = 距离 ÷ 时间。通常还需要变形公式求距离或时间，或者在代入数字前转换单位。
The basic formula appears in this form:
基本公式如下：
v = d / t
s = d / t (some WJEC papers use ‘s’ for speed)
v 或 s = d / t (部分 WJEC 试卷用 ‘s’ 表示速度)
Past‑paper example: A cyclist travels 450 metres in 30 seconds. Calculate his speed. Give the unit.
真题示例：一名自行车运动员 30 秒内行驶了 450 米。计算他的速度。并给出单位。
÷ 30 = 15. Step 3: add the correct unit: 15 m/s. Many candidates forget the unit or write ‘15 ms’ which is incorrect. Always write m/s.
步骤 1：写出公式 v = d/t。步骤 2：代入 d = 450 m，t = 30 s → v = 450 ÷ 30 = 15。步骤 3：添加正确单位：15 m/s。许多考生忘记写单位或写成 ‘15 ms’，这是错误的。一定要写 m/s。
paper asks for distance, rearrange to d = v × t. A common trap is to give time in minutes – you must convert to seconds first. For example, ‘5 minutes’ becomes 300 s.
如果试卷要求计算距离，变形为 d = v × t。常见陷阱是给出以分钟为单位的时间——你必须先转换成秒。例如 ‘5 分钟’ 变成 300 秒。
), hours to seconds (× 3600). The exam often mixes units to test your attention to detail.
练习转换：千米到米 (× 1000)，小时到秒 (× 3600)。考试经常混合单位以测试你对细节的注意力。
3. Interpreting Distance–Time Graphs | 解读距离–时间图
Distance–time graphs appear in nearly every Year 7 WJEC paper. A straight sloping line means constant speed; a horizontal line means the object is stationary (not moving). The steeper the slope, the greater the speed.
距离–时间图几乎出现在每份 Year 7 WJEC 试卷中。一条倾斜的直线表示匀速运动；水平线表示物体静止（不运动）。斜率越大，速度越快。
Typical question: Look at the graph. Between which two points is the car moving fastest? Explain your answer.
典型题目：看图。汽车在哪两个点之间运动最快？解释你的答案。
You must identify the section with the steepest gradient. Then explain: ‘The gradient of a distance–time graph represents speed. A steeper gradient means a larger distance is traveled in the same time, so the speed is higher.’ Answers need both the identification and the reasoning.
你必须找出斜率最大的部分。然后解释：‘距离–时间图的梯度代表速度。梯度越大，表示相同时间走过的距离越大，所以速度越快。’ 答案需要既有判断又有推理。
Another common task is to draw a graph: ‘Plot the data and draw a line of best fit.’ Do not connect dots with rigid zig‑zags; draw a smooth straight line passing through as many points as possible. If the line curves, use a smooth curve, not a series of straight segments.
另一个常见任务是画图：‘标出数据并画出最佳拟合线。’ 不要用生硬的锯齿线连接点；画一条光滑的尽可能通过大多数点的直线。如果线是弯曲的，用光滑曲线，而非一连串直线段。
formula speed = (change in distance) ÷ (change in time). Always show the coordinates used.
最后，你可能会被要求从图上取两点计算速度。使用公式 速度 = (距离变化) ÷ (时间变化)。务必展示所用坐标。
4. Forces: Balanced, Unbalanced and Friction | 力：平衡、不平衡与摩擦力
Year 7 WJEC Physics expects you to model forces with arrows. The length of the arrow shows the magnitude, the direction shows the way the force acts. When forces on an object are equal and opposite, they are balanced – the object remains at rest or moves at constant speed.
Year 7 WJEC 物理要求你会用箭头表示力。箭头的长度表示大小，方向表示力的作用方向。当作用在物体上的力大小相等方向相反时，它们平衡——物体保持静止或匀速运动。
Past‑paper question: A book rests on a table. Draw and label the forces acting on the book. You need a downward arrow for weight (gravity) and an upward arrow for the normal contact force from the table. Arrows must be equal length because the book is stationary.
真题示例：一本书放在桌子上。画出并标出作用在书上的力。 你需要一个向下的箭头表示重力（重量），一个向上的箭头表示桌面的法向接触力。由于书是静止的，箭头必须等长。
Unbalanced forces cause a change in motion – forces (weight = air resistance). Explain that the forces are equal at terminal velocity.
不平衡的力会引起运动变化——加速、减速或方向改变。摩擦力是常见的反作用力。匀速下落的跳伞员力是平衡的（重力 = 空气阻力）。解释在终极速度时力相等。
Be precise with terminology: use ‘ is not zero, the object accelerates. Example calculation: resultant force = driving force – friction. Use units of newtons (N).
使用精确术语：用 ‘resultant force’ 表示合力。如果合力不为零，物体加速。计算示例：合力 = 驱动力 – 摩擦力。单位用牛顿 (N)。
F_resultant = Fdrive – F_friction
合力 = 驱动力 − 摩擦力
5. Energy Stores, Transfers and Conservation | 能量储存、转移与守恒
WJEC Year 7 past papers often ask you to identify energy stores (kinetic, thermal, gravitational potential, chemical, elastic, nuclear) and describe how energy is transferred from one store to another. The principle of conservation of energy underpins every answer: energy is never created or destroyed, only transferred.
WJEC Year 7 历年真题常要求你识别能量储存形式（动能、热能、重力势能、化学能、弹性势能、核能）并描述能量如何从一个储存库转移到另一个。能量守恒原理是每个答案的基础：能量不能被创造或消灭，只能转移。
Example: Describe the energy transfers when a ball is thrown upwards. At the start, chemical energy in the thrower's muscles is transferred to kinetic energy of the ball. As it rises, kinetic energy decreases while gravitational potential energy increases. At the highest point, kinetic energy is minimum (but not necessarily zero) and GPE is maximum. Air resistance also transfers some kinetic energy to thermal energy of the surroundings.
示例：描述向上抛出一个球时的能量转移。 开始时，投掷者肌肉中的化学能转移为球的动能。上升时，动能减少而重力势能增加。在最高点，动能最小（但不一定为零），重力势能最大。空气阻力也将部分动能转移为周围环境的热能。
Always use correct store names. Write ‘thermal energy store’ rather than just ‘heat’. Diagrams may ask you to complete energy transfer pathways using arrows labelled with the transfer process (mechanically, electrically, by heating, by radiation).
始终使用正确的储存库名称。写 ‘thermal energy store’ 而非仅仅 ‘heat’。图表题可能要求你完成带箭头的能量转移路径，并标明转移过程（通过机械做功、电、加热、辐射）。
A common misconception is that objects ‘contain’ heat. Correct answer: objects have a thermal energy store; temperature is a measure of how hot it is, not the amount of energy. Past papers test this distinction rigorously.
一个常见误解是物体 ‘含有热’。正确答案：物体具有热能储存库；温度是冷热程度的量度，不是能量的多少。历年真题严格测试这一区别。
6. Electrical Circuits: Current, Voltage and Components | 电路：电流、电压和元件
Year 7 WJEC electric circuit questions concentrate on building and interpreting simple circuits. You must know symbols for cell, battery, lamp, switch, resistor, variable resistor and ammeter. Be able to draw them neatly with a ruler.
Year 7 WJEC 电路题侧重于构建和解读简单电路。你必须知道电池、电池组、灯泡、开关、电阻器、可变电阻器和电流表的符号，并能用直尺整齐地画出。
Typical past‑paper question: Draw a circuit diagram to measure the current through a lamp and the voltage across it. You need an ammeter in series with the lamp, and a voltmeter in parallel across the lamp. Many candidates incorrectly place the voltmeter in series, which would not measure the voltage correctly.
典型真题：画一个可以测量流过灯的电流和灯两端电压的电路图。 你需要一个与灯串联的电流表，和一个与灯并联的电压表。许多考生错误地将电压表串联，这无法正确测量电压。
Current (measured in amps, A) is the flow of electric charge. In a series circuit, current is the same everywhere. In a parallel circuit, current splits between branches. Understanding this conceptually is more important than numerical calculations at this stage.
电流（单位安培，A）是电荷的流动。在串联电路中，各处电流相等。在并联电路中，电流在支路间分流。在这个阶段，对这一概念的理解比数值计算更重要。
A classic tricky question: Add another lamp in parallel. What happens to the current through the battery? The total current increases because the circuit resistance decreases, providing more paths. Explanations must link to resistance and pathways, not just ‘it gets brighter’.
经典难题：并联接入另一盏灯，流过电池的电流会怎样？ 总电流增大，因为电路电阻减小，提供了更多路径。解释必须联系到电阻和路径，而不仅仅是‘它变得更亮’。
Voltage is the ‘push’ that drives current. A voltmeter reading across a component shows the energy transferred per unit charge. Use the phrase ‘potential difference (p.d.)’ as it is the formal term expected by WJEC.
电压是驱动电流的‘推力’。元件两端的电压表读数显示单位电荷转移的能量。使用 ‘potential difference (p.d.)’ 这个短语，因为它是 WJEC 期望的正式术语。
7. Thermal Energy Transfer: Conduction, Convection, Radiation | 热能传递：传导、对流、辐射
Past papers frequently include a scenario – such as a pan on a stove or a house losing heat – and ask you to explain how thermal energy travels. You need to distinguish clearly between conduction (mainly in solids), convection (in liquids and gases) and radiation (vacuum and transparent media).
历年真题常给出一个场景——比如炉子上的锅或房屋散热——并要求你解释热能如何传递。你需要清晰区分传导（主要在固体中）、对流（在液体和气体中）和辐射（真空和透明介质中）。
Example: Explain how the handle of a metal spoon gets hot when placed in a hot drink. The answer: ‘Thermal energy is transferred through the spoon by conduction. Vibrating particles in the hot part of the spoon pass on kinetic energy to neighbouring particles along the spoon, without the material itself moving.’
示例：解释当金属调羹放入热饮中时，勺柄如何变热。 答案：‘热能通过传导沿调羹传递。调羹热端振动着的粒子将动能传递给相邻的粒子，材料本身并不移动。’
For convection, you must describe the density change: fluid near the heat source expands, becomes less dense and rises. Cooler, denser fluid sinks to take its place, forming a convection current. Answers frequently lose marks for omitting the density explanation.
对于对流，你必须描述密度变化：靠近热源的流体膨胀，密度减小并上升。较冷、密度较大的流体下沉补充其位置，形成对流循环。答案常因遗漏密度解释而丢分。
Radiation involves infrared waves that can travel through empty space. Dark, matt surfaces are good emitters and absorbers; light, shiny surfaces are good reflectors and poor absorbers. A classic WJEC question: Why are solar panels often black? Answer: black is a good absorber of radiation, maximising the energy transferred.
辐射涉及可以在真空中传播的红外波。暗色粗糙表面是良好的发射体和吸收体；浅色光滑表面是良好的反射体，较差的吸收体。WJEC 经典题：为什么太阳能电池板通常是黑色的？ 答案：黑色是辐射的良好吸收体，能最大限度地转移能量。
8. Sound and Light: Wave Behaviour and Rays | 声音和光：波动行为和光线
Year 7 WJEC Physics treats sound and light as waves. Sound is a longitudinal wave that needs a medium; light is transverse and can travel through a vacuum. Diagrams often ask you to draw sound waves as compressions and rarefactions, or light rays as straight lines with arrows.
Year 7 WJEC 物理将声音和光视为波。声波是纵波，需要介质；光波是横波，可以在真空中传播。图表题常要求你画出声波的压缩和稀疏区域，或画出带箭头的光线直线。
Past‑paper task: Complete the ray diagram to show how a periscope works using two mirrors. lection must be obeyed: angle of incidence = angle of reflection. Marks are lost for forgetting arrowheads or drawing angles incorrectly.
真题任务：完成光线图，说明潜望镜如何使用两面镜子工作。 你需要画出入射光线以 45° 角射向第一面镜子，以相同角度反射到第二面镜子，然后进入眼睛。必须遵守反射定律：入射角 = 反射角。忘记标箭头或画错角度会丢分。
Sound questions often focus on pitch (frequency) and loudness (amplitude). A common graph‑reading exercise is to identify which wave has a higher pitch (more waves in the same time). Explain pitch in terms of frequency: ‘more vibrations per second means higher pitch’.
声音题常聚焦于音调（频率）和响度（振幅）。常见的读图练习是识别哪个波音调更高（相同时间内波更多）。用频率解释音调：‘每秒振动次数越多，音调越高’。
Another area is the ear: know that sound waves cause the eardrum to vibrate, which passes vibrations to the inner ear. Loud sounds can damage the eardrum, so hearing protection is needed. These straightforward recall questions are easy marks if you have revised.
另一个领域是耳朵：要知道声波引起鼓膜振动，振动传递到内耳。巨大的声音会损伤鼓膜，所以需要听力保护。这些直接回忆题只要复习过就能轻松得分。
Finally, remember that in a vacuum no one can hear you scream – sound cannot travel through space. Light from the sun, however, does reach us through the vacuum. Questions testing this difference appear almost every year.
最后，记住在真空中没人能听到你的尖叫——声音不能在太空中传播。然而太阳的光能通过真空到达我们。测试这一区别的题目几乎每年都出现。
Published by TutorHao | Physics Revision Series | aleveler.com
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