Year 10 WJEC Physics Core Knowledge Review | Year 10 WJEC 物理核心知识点梳理

📚 Year 10 WJEC Physics Core Knowledge Review | Year 10 WJEC 物理核心知识点梳理

This revision guide consolidates the essential topics from the Year 10 WJEC GCSE Physics specification. It covers the fundamentals of electric circuits, energy transfers and resources, wave behaviour, and optics. The content is aligned with the WJEC Unit 1 syllabus and is designed to help you build a solid foundation, whether you are preparing for end‑of‑year exams or simply reinforcing your understanding. Each section provides clear explanations, key equations, and practical examples to make the concepts easier to remember.

这份复习指南梳理了 Year 10 WJEC GCSE 物理课程的核心主题。内容涵盖电路基础、能量传递与能源资源、波的特性以及光学，完全对应 WJEC 第一单元考试大纲。无论你是在为学年末考试做准备，还是想巩固所学知识，本文都能帮助你打下扎实的基础。每个小节都提供了清晰的解释、关键公式和实际例子，让概念更容易记住。

1. Electric Circuits & Charge | 电路与电荷

An electric circuit is a closed loop that allows charge to flow continuously. Current is the rate of flow of electric charge, measured in amperes (A). For a current to exist, there must be a complete conducting path and a source of potential difference, such as a cell or battery. Charge is measured in coulombs (C), and one coulomb is the amount of charge that passes a point when a current of one ampere flows for one second.

电路是一个允许电荷持续流动的闭合回路。电流是电荷流动的速率，单位为安培（A）。要产生电流，必须有完整的导电路径和电势差来源，如电池。电荷的单位是库仑（C），1 库仑等于 1 安培电流在 1 秒内通过某一点的电荷量。

The relationship between charge, current and time is given by:

电荷、电流和时间的关系如下：

Q = I × t

where Q is charge in coulombs, I is current in amperes, and t is time in seconds. You will often be asked to calculate how much charge flows in a given time or how long a battery can supply a certain current.

其中 Q 为电荷（C），I 为电流（A），t 为时间（s）。考试中经常要求计算给定时间内流过的电荷量，或电池能提供特定电流的时长。

2. Current, Voltage & Resistance | 电流、电压与电阻

Voltage (or potential difference) is the energy transferred per unit charge. It is measured in volts (V). One volt means one joule of energy is transferred per coulomb of charge. Resistance opposes the flow of current and is measured in ohms (Ω). The three quantities are linked by Ohm’s Law: V = I × R.

电压（电势差）是单位电荷转移的能量，单位为伏特（V）。1 伏特表示每库仑电荷转移 1 焦耳能量。电阻阻碍电流流动，单位为欧姆（Ω）。这三个量通过欧姆定律关联：V = I × R。

For a fixed resistor, current is directly proportional to voltage, provided the temperature remains constant. Components such as diodes and filament lamps do not obey Ohm’s law because their resistance changes with current. A diode only allows current to flow in one direction, while a filament lamp’s resistance increases as it heats up.

对于固定电阻，在温度恒定时，电流与电压成正比。二极管和灯丝灯泡等元件不遵循欧姆定律，因为它们的电阻会随电流改变。二极管只允许电流单向流动，而灯丝的电阻会随着温度升高而增大。

3. Series & Parallel Circuits | 串联与并联电路

In a series circuit, components are connected end‑to‑end, so there is only one path for current. The current is the same at all points, the total resistance is the sum of individual resistances, and the supply voltage is shared across components.

在串联电路中，元件首尾相连，电流只有一条路径。电路中各处电流相等，总电阻等于各个电阻之和，电源电压被分配到各元件上。

In a parallel circuit, components are connected on separate branches. The voltage across each branch is the same as the supply voltage. The total current is the sum of the currents in the branches, and the total resistance is always less than the smallest individual resistance.

在并联电路中，各元件位于不同的支路上。各支路两端电压等于电源电压。总电流等于各支路电流之和，总电阻始终小于最小的单个电阻。

Understanding these rules is vital for solving circuit problems:

理解这些规则对解答电路题至关重要：

Series: Rₜₒₜ = R₁ + R₂ + …    Parallel: 1/Rₜₒₜ = 1/R₁ + 1/R₂ + …

4. Domestic Electricity & Safety | 家庭用电与安全

Mains electricity in the UK is supplied at 230 V with a frequency of 50 Hz as an alternating current (a.c.). The three‑pin plug contains a live wire (brown), a neutral wire (blue) and an earth wire (green and yellow stripes). The earth wire provides a low‑resistance path to ground if a fault occurs, which helps blow the fuse or trip the circuit breaker and prevents electric shock.

英国市电为 230 V、50 Hz 的交流电。三脚插头包含火线（棕色）、零线（蓝色）和地线（黄绿条纹）。当发生故障时，地线提供一条低电阻接地通路，能促使保险丝熔断或断路器跳闸，防止触电。

Fuses and circuit breakers are safety devices that disconnect the circuit if the current becomes too high. The rating of a fuse should be slightly above the normal operating current of the appliance. Double‑insulated appliances do not require an earth wire because their casing is made of insulating material.

保险丝和断路器是当电流过大时断开电路的安全装置。保险丝的额定电流应略高于电器的正常工作电流。双重绝缘电器外壳为绝缘材料，因此不需要地线。

5. Electrical Power & Energy | 电功率与电能

Power is the rate at which energy is transferred. In electrical circuits, power can be calculated using:

功率是能量传递的速率。在电路中，功率可以用以下公式计算：

P = I × V    and    P = I² × R

where P is power in watts (W), I is current in amperes, V is voltage in volts, and R is resistance in ohms. The energy transferred is given by E = P × t, where t is time in seconds. The kilowatt‑hour (kWh) is a unit of energy often used for electricity bills: 1 kWh = 3.6 million joules.

其中 P 为功率（W），I 为电流（A），V 为电压（V），R 为电阻（Ω）。转移的能量 E = P × t，t 以秒为单位。千瓦时（kWh）是电费单上常用的能量单位：1 kWh = 360 万焦耳。

6. Energy Transfers & Efficiency | 能量转移与效率

Energy can be stored in different forms—kinetic, thermal, chemical, gravitational potential, elastic potential, and nuclear—and it can be transferred by heating, by waves, or by an electric current. In any transfer, the total energy is conserved, but some energy is almost always dissipated (spread out) as thermal energy, making the process less useful.

能量可以以不同形式储存——动能、热能、化学能、重力势能、弹性势能和核能——并通过加热、波或电流进行转移。在任何转移过程中，总能量守恒，但总有一部分能量以热能的形式耗散，使过程效率降低。

Efficiency is the proportion of input energy (or power) that is converted to useful output. It can be expressed as a decimal or a percentage:

效率是输入能量（或功率）转化为有用输出的比例，可用小数或百分比表示：

Efficiency = Useful output energy / Total input energy

Sankey diagrams visually represent energy transfers, with arrow widths proportional to the amounts of energy. The wasted energy arrow points downwards or to the side.

桑基图形象地展示能量传递，箭头宽度与能量大小成正比，浪费的能量箭头朝下或朝侧向。

7. Energy Resources & Generating Electricity | 能源资源与发电

Energy resources are classified as renewable or non‑renewable. Fossil fuels (coal, oil, natural gas) and nuclear fuel are non‑renewable because they are finite. Renewable sources include wind, solar, tidal, hydroelectric, wave and geothermal. Each resource has advantages and disadvantages in terms of reliability, cost, environmental impact, and carbon emissions.

能源资源分为可再生能源和不可再生能源。化石燃料（煤、石油、天然气）和核燃料因储量有限而属于不可再生能源。可再生能源包括风能、太阳能、潮汐能、水能、波浪能和地热能。每种能源在可靠性、成本、环境影响和碳排放方面各有优劣。

In most power stations, thermal energy from burning fuel or nuclear reactions is used to heat water into steam, which drives a turbine connected to a generator. Renewable sources like wind and hydro use kinetic energy directly. The National Grid distributes electricity across the country at high voltage to minimise energy losses.

多数发电站利用燃料燃烧或核反应产生的热能加热水生成蒸汽，驱动与发电机相连的涡轮。风能和水能等可再生能源则直接利用动能。国家电网以高电压输送电力以减少能量损耗。

8. Wave Properties | 波的特性

Waves transfer energy from one place to another without transferring matter. Transverse waves have oscillations perpendicular to the direction of energy transfer (e.g. light, water waves, all electromagnetic waves). Longitudinal waves have oscillations parallel to the direction of energy transfer (e.g. sound waves).

波传递能量而不传递物质。横波的振动方向与能量传递方向垂直（如光、水波、所有电磁波）。纵波的振动方向与能量传递方向平行（如声波）。

Key wave quantities are amplitude, wavelength, frequency, and wave speed. The wave equation is:

描述波的关键量包括振幅、波长、频率和波速。波动方程为：

v = f × λ

where v is wave speed (m/s), f is frequency (Hz), and λ is wavelength (m). Frequency is the number of complete waves passing a point per second; period (T) = 1/f.

其中 v 为波速（m/s），f 为频率（Hz），λ 为波长（m）。频率是每秒通过某点的完整波的数量；周期 T = 1/f。

9. The Electromagnetic Spectrum | 电磁波谱

The electromagnetic spectrum is a continuous range of transverse waves that all travel at the same speed in a vacuum (3 × 10⁸ m/s). In order of decreasing wavelength and increasing frequency, the groups are: radio waves, microwaves, infrared, visible light, ultraviolet, X‑rays and gamma rays. The higher the frequency, the more energy the wave carries.

电磁波谱是一系列连续的横波，在真空中传播速度相同（3 × 10⁸ m/s）。按照波长递减、频率递增的顺序排列为：无线电波、微波、红外线、可见光、紫外线、X 射线和伽马射线。频率越高，波携带的能量越大。

Different parts of the spectrum are used for different applications: radio waves for broadcasting, microwaves for cooking and communications, infrared for remote controls and thermal imaging, visible light for vision, ultraviolet for detecting forged bank notes and sterilising, X‑rays for medical imaging, and gamma rays for cancer treatment and sterilising medical equipment. You need to know both the uses and the dangers associated with each region.

不同波段的电磁波有不同用途：无线电波用于广播，微波用于烹饪和通信，红外线用于遥控和热成像，可见光用于视觉，紫外线用于验钞和消毒，X 射线用于医学成像，伽马射线用于治疗癌症和医疗器械灭菌。你需要了解各波段的用途和危害。

10. Reflection & Refraction | 反射与折射

When waves meet a boundary between two media, they can be reflected or refracted. The law of reflection states that the angle of incidence equals the angle of reflection, measured from the normal (a line perpendicular to the surface). This applies to all types of waves, including light and sound.

波遇到两种介质的交界面时，会发生反射或折射。反射定律指出入射角等于反射角，角度从法线（垂直于界面的线）量起。这一定律适用于所有波，包括光波和声波。

Refraction occurs when a wave enters a new medium at an angle and changes speed. If the wave slows down, it bends towards the normal; if it speeds up, it bends away from the normal. The change in direction is due to the change in speed, not a change in frequency. For example, light slows down when it enters glass from air, causing it to bend towards the normal.

当波以一定角度进入新介质并改变速度时，会发生折射。波速减慢时，朝着法线方向偏折；波速加快时，远离法线偏折。方向的改变是由于速度的变化，而非频率的改变。例如，光从空气进入玻璃时速度减慢，朝法线方向偏折。

Total internal reflection (TIR) occurs when light travels from a denser medium to a less dense medium at an angle of incidence greater than the critical angle. This principle is used in optical fibres and endoscopes.

当光从光密介质到光疏介质且入射角大于临界角时，会发生全内反射。这一原理用于光纤和内窥镜。

11. Lenses & Image Formation | 透镜与成像

Convex (converging) lenses bring parallel rays of light together at a focal point. The distance from the lens to the focal point is the focal length. A convex lens can produce real or virtual images depending on the object distance. Concave (diverging) lenses always produce virtual, diminished, and upright images.

凸透镜（会聚透镜）将平行光线会聚于焦点。透镜到焦点的距离称为焦距。根据物距不同，凸透镜可以产生实像或虚像。凹透镜（发散透镜）始终产生正立、缩小的虚像。

You should be able to draw ray diagrams to show how a convex lens forms an image when the object is placed beyond 2F, at 2F, between F and 2F, and inside F. In a magnifying glass, the object is placed inside the focal length, producing a virtual, upright, and magnified image.

你需要会画光路图，展示物体位于 2 倍焦距外、2 倍焦距处、焦距与 2 倍焦距之间以及焦距以内时，凸透镜如何成像。放大镜的物体放置在焦距以内，产生正立、放大的虚像。

The magnification produced by a lens can be calculated using:

透镜产生的放大率可用以下公式计算：

Magnification = Image height / Object height

No units; magnification greater than 1 means the image is larger than the object.

放大率没有单位；大于 1 表示像比物大。

Published by TutorHao | Physics Revision Series | aleveler.com

更多咨询请联系16621398022（同微信）