📚 Pre-U OCR Physics: Vocabulary & Terminology Quick-Memorisation Guide | Pre-U OCR 物理：词汇术语速记指南
Mastering the precise language of physics is half the battle in Pre-U OCR exams. This guide breaks down essential terminology from across the syllabus, pairing each term with a memorable explanation, contextual use, and learning hacks. Whether you are revisiting mechanics, waves, fields, or modern physics, these paired English and Chinese notes will help you lock in definitions, avoid common slip-ups, and write answers that examiners respect.
在 Pre-U OCR 物理考试中，精准掌握学科术语是成功的一半。本指南将教学大纲中的核心词汇逐一拆解，每个术语都配有易记的解释、情境用法和学习窍门。无论你正在复习力学、波动、场论还是近代物理，这些中英对照笔记都能帮你牢牢记住定义，避开常见错误，写出考官青睐的回答。
1. Mechanics and Motion | 力学与运动
Displacement is a vector quantity representing the shortest straight-line distance from the initial to the final position, together with its direction. It differs from distance, which is scalar and measures the total path length travelled. A runner completing one full lap on a 400 m track has a distance of 400 m but a displacement of 0 m.
位移是矢量，表示从初位置到末位置的最短直线距离及其方向。它与路程（标量，量度运动轨迹总长度）不同。在 400 m 跑道上跑完一整圈的运动员，路程是 400 m，而位移是 0 m。
Velocity is the rate of change of displacement, so it is also a vector. Acceleration is the rate of change of velocity and can result from a change in speed or direction. Uniform circular motion involves constant speed but changing velocity, giving centripetal acceleration a = v²/r directed towards the centre.
速度是位移的变化率，因此也是矢量。加速度是速度的变化率，可由速率或方向的改变引起。匀速圆周运动具有恒定速率但不断变化的速度，产生指向圆心的向心加速度 a = v²/r。
Momentum p = m v is conserved in all isolated systems. Impulse is the change in momentum, equal to the average force multiplied by the time for which it acts: FΔt = Δp. The area under a force–time graph gives impulse. In collisions, use conservation of momentum alongside kinetic energy checks to identify whether the collision is elastic or inelastic.
动量 p = m v 在所有孤立系统中守恒。冲量是动量的变化量，等于平均力乘以力的作用时间：FΔt = Δp。力–时间图下的面积代表冲量。处理碰撞问题时，既要运用动量守恒，也要结合动能分析来判断碰撞是弹性还是非弹性的。
2. Fields and Forces | 场与力
A field is a region in which an object experiences a non-contact force. Gravitational field strength g = F/m is a vector directed towards the centre of mass. Electric field strength E = F/q points away from positive charges. Remember: g and E are force per unit mass and force per unit charge respectively. Their units, N kg⁻¹ and N C⁻¹, are equivalent to m s⁻² and V m⁻¹.
场是物体受到非接触力的区域。引力场强度 g = F/m 是指向质量中心的矢量。电场强度 E = F/q 的方向远离正电荷。记牢：g 和 E 分别是单位质量力和单位电荷力。它们的单位 N kg⁻¹ 和 N C⁻¹ 分别等同于 m s⁻² 和 V m⁻¹。
Coulomb’s law F = kQq/r² mirrors Newton’s law of gravitation F = GmM/r² in its inverse-square form. In both, the force is proportional to the product of the two ‘charge-like’ quantities and inversely proportional to the square of separation. Electric potential V = kQ/r and gravitational potential V_g = –Gm/r share the same mathematical structure, but gravitational potential is negative because gravity is always attractive.
库仑定律 F = kQq/r² 在平方反比形式上与牛顿万有引力定律 F = GmM/r² 一致。两者都是力正比于两个“荷”量的乘积，反比于距离的平方。电势 V = kQ/r 和引力势 V_g = –Gm/r 具有相同的数学结构，但引力势为负值，因为引力始终是吸引力。
Equipotential surfaces are imaginary surfaces on which the potential is constant. No work is done moving a charge or mass along an equipotential. Field lines are always perpendicular to equipotentials. In diagrams, closer field lines indicate stronger fields. For exam answers, explicitly state ‘field lines show direction of the force on a positive test charge’ or ‘on a small test mass’.
等势面是势能处处相等的假想曲面。沿等势面移动电荷或质量不做功。场线始终与等势面垂直。图示中场线越密，场强越大。考试作答时务必明确说明“电场线表示正试探电荷所受力的方向”或“引力场线表示小试探质量所受力的方向”。
3. Oscillations and Waves | 振动与波
Simple harmonic motion (SHM) occurs when acceleration is directly proportional to displacement from equilibrium and always directed towards equilibrium: a ∝ –x. The defining equation a = –ω²x leads to sinusoidal variations of x, v and a with time. Key phrases to use: ‘the restoring force is proportional to displacement’ and ‘the acceleration is always towards the equilibrium position’.
简谐运动发生在加速度与偏离平衡位置的位移成正比且始终指向平衡位置时：a ∝ –x。由定义式 a = –ω²x 可导出 x、v 和 a 随时间正弦变化。答题关键词：“回复力与位移成正比”、“加速度始终指向平衡位置”。
Amplitude is the maximum displacement from equilibrium. Period T = 2π/ω is the time for one complete oscillation. Frequency f = 1/T. Phase difference describes how much one oscillator leads or lags another. For a wave, the relationship v = fλ is universal, but remember that wave speed depends only on the medium for mechanical waves, while frequency is determined by the source.
振幅是偏离平衡位置的最大位移。周期 T = 2π/ω 是一次完整振动的时间。频率 f = 1/T。相位差描述了两个振子之间的超前或滞后关系。对波而言，关系式 v = fλ 普遍适用，但要记住机械波的波速仅由介质决定，而频率由波源决定。
Transverse waves have oscillations perpendicular to energy transfer (e.g. light, water waves). Longitudinal waves have oscillations parallel to energy transfer (e.g. sound). Polarisation only works for transverse waves and is evidence for the orientation of oscillations. Standing waves form from the superposition of two identical travelling waves moving in opposite directions; nodes have zero amplitude, antinodes maximum amplitude.
横波的振动方向与能量传递方向垂直（例如光波、水波）。纵波的振动方向与能量传递方向平行（例如声波）。偏振只适用于横波，可作为证明振动方向的证据。驻波由两列相同的行波反向叠加形成；波节振幅为零，波腹振幅最大。
4. Thermal Physics | 热物理
Internal energy is the sum of the random distribution of kinetic and potential energies of the molecules in a system. The kinetic part relates to temperature; the potential part relates to intermolecular forces and phase. During a phase change, temperature remains constant because the added energy increases only the potential component, breaking bonds rather than raising kinetic energy.
内能是系统内分子无规则分布的动能与势能之和。动能部分与温度相关；势能部分与分子间作用力和物态相关。在相变过程中，温度保持不变，因为加入的能量仅增加势能部分，用于破坏分子间键，而不是提升动能。
Specific heat capacity c is the energy needed to raise 1 kg of a substance by 1 K without a change of state: Q = mcΔθ. Specific latent heat L is the energy per unit mass required to change state at constant temperature: Q = mL. Use ‘specific’ only when referring to per unit mass. Avoid confusing ‘heat’ and ‘temperature’ in definitions; temperature is a measure of average kinetic energy, not heat.
比热容 c 是使 1 kg 物质在无物态变化的情况下升高 1 K 所需能量：Q = mcΔθ。比潜热 L 是恒温下单位质量物质物态变化所需的能量：Q = mL。“比”字专指每单位质量。在定义中避免混淆“热量”与“温度”；温度是平均动能的量度，而非热量。
The ideal gas equation pV = nRT = NkT links pressure, volume, amount of substance and temperature. The Boltzmann constant k = R/Nₐ. The kinetic theory model gives pV = ⅓ N m ⟨c²⟩, linking macroscopic pressure to the mean square speed of molecules. Note that T ∝ average translational KE; thus absolute zero is the point where particle motion theoretically ceases.
理想气体方程 pV = nRT = NkT 将压强、体积、物质的量和温度联系起来。玻尔兹曼常量 k = R/Nₐ。气体动理论模型给出 pV = ⅓ N m ⟨c²⟩，将宏观压强与分子的方均速度联系在一起。注意 T ∝ 平均平移动能；因此绝对零度是粒子运动在理论上停止的温度。
5. Electricity and Circuits | 电学与电路
Current I is the rate of flow of charge: I = ΔQ/Δt. In metals, it is carried by delocalised electrons, but in electrolytes it can be carried by ions. Potential difference (p.d.) V between two points is the energy transferred per unit charge: V = W/Q. Electromotive force (e.m.f.) is the energy supplied per unit charge by a source in converting non-electrical energy to electrical energy.
电流 I 是电荷的流动率：I = ΔQ/Δt。在金属中载流子是自由电子，而在电解质中可以是离子。两点之间的电势差（p.d.）V 是每单位电荷传递的能量：V = W/Q。电动势（e.m.f.）是电源将非电能转化为电能时每单位电荷所提供的能量。
Resistance R = V/I, and for ohmic conductors at constant temperature this ratio is constant. Resistivity ρ is the resistance multiplied by cross-sectional area divided by length: R = ρL/A. Semiconductors have resistance that decreases with rising temperature, unlike metals. Kirchhoff’s laws: first law (current conservation) ΣI_in = ΣI_out; second law (energy conservation) Σε = ΣIR around any closed loop.
电阻 R = V/I，对恒温下的欧姆导体该比值为常量。电阻率 ρ 是电阻乘以横截面积除以长度：R = ρL/A。半导体电阻随温度升高而降低，与金属相反。基尔霍夫定律：第一定律（电流守恒）ΣI_in = ΣI_out；第二定律（能量守恒）沿任一闭合回路 Σε = ΣIR。
Potential divider circuits split voltage according to resistance ratios. The output voltage V_out = V_in × (R₂/(R₁+R₂)). Use a thermistor or LDR in a potential divider to create temperature- or light-sensitive circuits. Internal resistance r of a source causes terminal p.d. V = ε – Ir; plotting V against I gives a straight line with gradient –r and y-intercept ε.
分压电路按电阻比分压。输出电压 V_out = V_in × (R₂/(R₁+R₂))。在分压电路中使用热敏电阻或光敏电阻可以构建温敏或光敏电路。电源的内阻 r 导致端电压 V = ε – Ir；以 V 对 I 作图得到斜率为 –r、y 截距为 ε 的直线。
6. Electromagnetism | 电磁学
Magnetic flux density B is defined by the force on a current-carrying conductor: F = BIL sinθ, where θ is the angle between current and field. The unit tesla (T) is N A⁻¹ m⁻¹. For a moving charge, F = BQv sinθ. Fleming’s left-hand rule gives the direction of force: thumb – force, first finger – field, second finger – conventional current.
磁通量密度 B 由来定义于载流导体所受的力：F = BIL sinθ，其中 θ 是电流方向与磁场方向的夹角。其单位特斯拉（T）为 N A⁻¹ m⁻¹。对运动电荷，F = BQv sinθ。弗莱明左手定则给出力的方向：拇指——力，食指——磁场，中指——常规电流。
Magnetic flux Φ = BA cosθ, where θ is the angle between field lines and the normal to area A. Flux linkage is NΦ. Faraday’s law states that induced e.m.f. equals the negative rate of change of flux linkage: ε = –d(NΦ)/dt. Lenz’s law, embedded in the minus sign, says that the induced current opposes the change producing it. This is a common examination explanatory question, so memorise the exact wording: ‘The direction of the induced e.m.f. is such that it produces effects that oppose the change in magnetic flux producing it.’
磁通量 Φ = BA cosθ，θ 是场线与面积 A 法线的夹角。磁链为 NΦ。法拉第定律指出，感应电动势等于磁链变化率的负值：ε = –d(NΦ)/dt。负号中的楞次定律表明，感应电流的方向总是阻碍引起它的磁通量变化。这是常见的简答题考点，要熟记准确表述：“感应电动势的方向总是使其产生的作用阻碍引起它的磁通量变化。”
Transformers operate on alternating flux linkage. For an ideal transformer, V_s/V_p = N_s/N_p = I_p/I_s. Eddy current losses can be reduced by laminating the core. Explain step-up and step-down in terms of turns ratio. Be ready to discuss efficiency and energy losses, especially in power transmission contexts.
变压器依靠交变磁链工作。理想变压器满足 V_s/V_p = N_s/N_p = I_p/I_s。涡流损耗可通过叠片铁芯来降低。用匝数比解释升压与降压。准备好在输电情境下讨论效率与能量损耗。
7. Atomic and Nuclear Physics | 原子与核物理
Photoelectric emission occurs when light of frequency above the threshold frequency f₀ ejects electrons from a metal surface. Einstein’s photoelectric equation: hf = Φ + ½ m v_max², where Φ = hf₀ is the work function. Key point: maximum kinetic energy depends only on frequency, not intensity. Intensity determines the rate of photoelectron emission. Use the term ‘photon’ and ‘quantum of energy’ consistently.
当频率高于截止频率 f₀ 的光照射金属表面时，会发射光电子。爱因斯坦光电方程：hf = Φ + ½ m v_max²，其中 Φ = hf₀ 是功函数。关键点：最大动能仅取决于频率，与光强无关。光强决定光电子发射率。答题时始终使用“光子”和“能量量子”的说法。
Atomic line spectra provide evidence for discrete energy levels. Emission spectra are bright lines on dark background; absorption spectra are dark lines on continuous background. The energy of a photon emitted or absorbed in a transition between levels is ΔE = hf = E₂ – E₁. For hydrogen-like atoms, energy levels scale with 1/n². Understand how excitation and ionisation energies differ.
原子线状光谱为分立能级提供了证据。发射光谱是暗背景上的亮线；吸收光谱是连续背景上的暗线。能级跃迁时发射或吸收的光子能量为 ΔE = hf = E₂ – E₁。对类氢原子，能级与 1/n² 成比例。分清激发能（excitation）和电离能（ionisation）的区别。
In nuclear physics, mass defect is the difference between the mass of a nucleus and the sum of masses of its individual nucleons. This missing mass appears as binding energy, given by E = mc². Binding energy per nucleon peaks around iron (Fe-56), making it the most stable nucleus. In fission and fusion, products have greater binding energy per nucleon, releasing energy.
在核物理中，质量亏损是原子核的质量与其各核子质量之和的差值。这部分质量以结合能的形式出现，满足 E = mc²。每核子的平均结合能在铁-56 附近达到峰值，使其成为最稳定的核。在裂变和聚变中，生成物具有更高的每核子结合能，因此释放能量。
8. Units and Measurements | 单位与测量
The SI base units are metre (m), kilogram (kg), second (s), ampere (A), kelvin (K), mole (mol) and candela (cd). All other quantities can be expressed in these. Common derived units: newton N = kg m s⁻², joule J = N m = kg m² s⁻², coulomb C = A s, volt V = J C⁻¹ = kg m² s⁻³ A⁻¹. Be able to express resistivity ρ in base units: Ω m → kg m³ s⁻³ A⁻².
SI 基本单位是米（m）、千克（kg）、秒（s）、安培（A）、开尔文（K）、摩尔（mol）和坎德拉（cd）。其他所有物理量均可用它们表示。常见导出单位：牛顿 N = kg m s⁻²，焦耳 J = N m = kg m² s⁻²，库仑 C = A s，伏特 V = J C⁻¹ = kg m² s⁻³ A⁻¹。应能写出电阻率 ρ 的基本单位表达式：Ω m → kg m³ s⁻³ A⁻²。
Homogeneity of equations: every term in a physical equation must have the same base units. Use dimensional analysis to check answers. For example, the period of a pendulum T = 2π√(L/g) gives units √(m / (m s⁻²)) = s, which is correct. When designing experiments, precision refers to the spread of repeated measurements, accuracy to closeness to the true value, and sensitivity to the smallest detectable change.
方程的量纲一致性：物理方程中的每一项都必须具有相同的基本单位。可用量纲分析来检查答案。比如单摆周期 T = 2π√(L/g) 的单位为 √(m / (m s⁻²)) = s，是正确的。在设计实验时，精度（precision）指重复测量值的分散程度，准度（accuracy）指与真值的接近程度，灵敏度（sensitivity）指能检测到的最小变化。
9. Memory Techniques for Equations | 公式记忆技巧
Use mnemonic stories and ‘shape’ patterns. For example, the SUVAT equations are linked: v = u + at looks like a linear equation; s = ut + ½at² has the ½ and square reminding you of integration from v = u + at. Associate v² = u² + 2as with an energy-type relation (no time). Practise deriving one from another to strengthen memory.
使用记忆故事和“形状”模式。例如，运动学五个方程彼此关联：v = u + at 像一次函数；s = ut + ½at² 中的 ½ 和平方可联想到由 v = u + at 积分得来。把 v² = u² + 2as 与不含时间的能量类关系联系起来。通过相互推导来增强记忆。
For electrical power, remember the ‘PIV WHEEL’: P = IV, then substitute V = IR to get P = I²R, or I = V/R to get P = V²/R. For wave optics, d sinθ = nλ uses ‘d sin theta equals n lambda’. A simple rhyme: ‘D-sine-n-lambda’ for constructive interference. For grating maximum, the formula is the same but d is grating spacing 1/N.
对于电功率，借助“PIV 轮”：P = IV，然后用 V = IR 代入得到 P = I²R，或用 I = V/R 得到 P = V²/R。对于波动光学，d sinθ = nλ，可念成“d sinθ 等于 nλ”。自编口诀：”d-sine-n-lambda” 对应干涉加强条件。光栅方程一致，但 d 代表光栅间距 1/N。
For SHM, remember ‘Max a, min v at extremes; max v, zero a at centre’. The displacement equations x = A cos(ωt) or x = A sin(ωt) depend on initial conditions. Link v_max = ωA and a_max = ω²A. Units: ω in rad s⁻¹ gives T = 2π/ω in seconds. Always check that radians are used in angular frequency.
对于简谐运动，记住“极端处加速度最大速度为零；平衡点处速度最大加速度为零”。位移方程 x = A cos(ωt) 或 x = A sin(ωt) 取决于初条件。联系 v_max = ωA 和 a_max = ω²A。注意 ω 单位是 rad s⁻¹，于是 T = 2π/ω 以秒为单位。始终检查角频率是否采用弧度制。
10. Common Prefixes and Suffixes | 常用前缀与后缀
SI prefixes from pico to tera must be second nature: pico (p, 10⁻¹²), nano (n, 10⁻⁹), micro (µ, 10⁻⁶), milli (m, 10⁻³), centi (c, 10⁻²), kilo (k, 10³), mega (M, 10⁶), giga (G, 10⁹), tera (T, 10¹²). In calculations, convert all quantities to base units first: milli is ×10⁻³, micro ×10⁻⁶, etc. A common mistake is misplacing a factor of 10³ when handling resistance (kΩ) and capacitance (µF).
从皮到太的 SI 词头必须熟练掌握：皮 p 10⁻¹²，纳 n 10⁻⁹，微 µ 10⁻⁶，毫 m 10⁻³，厘 c 10⁻²，千 k 10³，兆 M 10⁶，吉 G 10⁹，太 T 10¹²。计算时首先把所有量化为基本单位：毫 ×10⁻³，微 ×10⁻⁶ 等。常见错误是计算电阻（kΩ）和电容（µF）时搞错 10³ 的因子。
Suffixes like ‘-ivity’ vs ‘-ance’ often confuse. Resistivity (ρ) is a material property independent of shape; resistance (R) depends on length and area. Similarly, conductivity σ = 1/ρ is the material’s ability to conduct; conductance G = 1/R depends on dimensions. Permittivity ε of a medium is a material property; capacitance C is the device property.
后缀“-ivity”与“-ance”常让人混淆。电阻率（ρ）是独立于形状的材料属性；电阻（R）取决于长度和面积。同理，电导率 σ = 1/ρ 是材料的导电能力；电导 G = 1/R 取决于尺寸。介质的电容率 ε 是材料属性；电容 C 是器件属性。
The suffix ‘-or’ often describes a device: resistor, capacitor, inductor, detector, thermistor. Words ending in ‘-meter’ measure a quantity: ammeter (current), voltmeter (p.d.), spectrometer (spectrum). A ‘potentiometer’ can be a voltage divider or a precise measuring instrument. Ensure you correctly distinguish between ‘oscilloscope’ (display) and ‘oscillator’ (source).
后缀“-or”常表示器件：电阻器（resistor）、电容器（capacitor）、电感器（inductor）、探测器（detector）、热敏电阻（thermistor）。以“-meter”结尾的词用于测量某物理量：安培表（ammeter）、伏特表（voltmeter）、光谱仪（spectrometer）。”potentiometer”既可指分压器，也可指精密测量仪器。务必区分“oscilloscope”（示波器，显示设备）和“oscillator”（振荡器，信号源）。
11. Exam Tips for Terminology | 考试术语应试技巧
Pre-U OCR papers often ask for definitions ‘in terms of …’, requiring precise wording. For instance, ‘Define the volt’ should be answered: ‘The potential difference across a component when 1 joule of energy is transferred per coulomb of charge passing through it.’ Never write just ‘unit of voltage’. Practise writing definitions with quantities and units explicitly mentioned.
Pre-U OCR 试卷常出现“用……定义……”的题型，要求精准措辞。例如“定义伏特”应作答：“当 1 库仑电荷通过某元件时转移 1 焦耳能量而具有的该元件两端的电势差。”切勿只写“电压的单位”。练习定义题时要明确写出物理量和单位。
When using analogies, state limitations. For example, the water circuit analogy for electricity is useful but does not capture electron drift speed or energy per charge concepts perfectly. In ‘explain’ questions, link cause and effect clearly. Use phrases like ‘this induces …’, ‘as a result …’, ‘because field lines are closer …’.
使用类比时要说明其局限性。例如，用水流类比电路虽然有用，但不能完美描述电子漂移速度或单位电荷能量的概念。在“解释”类题目中，要清晰地连接因果。多用“这感应出……”、“结果是……”、“因为场线更密……”等句式。
Command words are critical. ‘State’ means give a concise fact; ‘describe’ requires a step-by-step account; ‘explain’ demands reasons or mechanisms; ‘calculate’ needs numerical working; ‘determine’ may involve a logical chain or a graph. For ‘suggest’, apply physics principles to a novel scenario. Always read the stem carefully for clues about expected terminology, and mirror that language in your answer.
指令词至关重要。”State”（陈述）要求给出简洁的事实；”describe”（描述）需要逐步叙述；”explain”（解释）要给出原因或机制；”calculate”（计算）要有数值步骤；”determine”（确定）可能涉及逻辑推理或图像分析。遇到”Suggestion”（建议）题，要把物理原理应用到新情境中。仔细阅读题干，从中寻找术语暗示，在答案中使用一致的语言。
12. Visualising and Connecting Concepts | 概念可视化与关联
Draw concept maps linking terms: connect ‘conservation of energy’ to ‘work done’, ‘internal energy’, ‘first law of thermodynamics’ and ‘efficiency’. For each topic, list the ‘key equation’, the ‘key graph’ and the ‘key practical’. For instance, in simple harmonic motion: T = 2π√(m/k), the velocity–displacement graph is an ellipse, and the oscillating spring practical validates the period formula.
绘制概念图将术语联系起来：将“能量守恒”与“做功”、“内能”、“热力学第一定律”和“效率”相关联。每个专题都列出“核心方程”、“核心图像”和“核心实验”。例如简谐运动：T = 2π√(m/k)，速度–位移图像为椭圆，弹簧振子实验验证了周期公式。
Use the ‘Feynman technique’: teach a term to an imaginary audience in simple language. If you can explain ‘hysteresis’ in terms of magnetic domain realignment lag, or ‘damping’ as energy removal from an oscillating system, you truly understand it. Keep a glossary notebook with two columns: formal definition and ‘plain English’ version.
运用“费曼技巧”：用简单的语言把术语教给想象中的听众。如果你能用磁畴重排滞后解释“磁滞”，或者将“阻尼”描述为从振动系统中移除能量，那就真的理解了。准备一本词汇簿，分两栏：正式定义和“通俗英语”版本。
Finally, practise past paper questions under timed conditions. Pay attention to mark schemes—they reveal acceptable phrasing, common errors, and precise vocabulary expectations. Review your mistakes and note any terminology you misused. Consistent revision of these terms using active recall and spaced repetition will build the confidence needed to excel in the Pre-U OCR Physics exam.
最后，定时练习历年真题。注意评分方案——它会揭示可接受的表述、常见错误和精准词汇的要求。回顾错误并记录误用的术语。用主动回忆和间隔重复的方法持续复习这些术语，你就能建立起在 Pre-U OCR 物理考试中取得优异成绩所需的信心。
Published by TutorHao | Physics Revision Series | aleveler.com
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