GCSE Physics Required Practicals 1-10: The Complete Guide
GCSE物理考试中,必做实验(Required Practicals)占据了试卷约15%的分数。AQA考试局明确列出10个核心实验,涵盖力学、热学、电学、波动物理四大领域。本文为你逐一拆解每个实验的实验目的、操作步骤、关键变量、常见错误和考试得分技巧,助你实验题拿满分!
In the GCSE Physics exam, Required Practicals account for roughly 15% of the marks. The AQA exam board specifies 10 core experiments spanning mechanics, thermal physics, electricity, and waves. This article breaks down each practical — aim, method, key variables, common mistakes, and exam scoring tips — to help you secure full marks on practical questions!
实验一:比热容测定 | RP1: Specific Heat Capacity
实验目的 Aim:测定固体材料(如铝块)的比热容。Determine the specific heat capacity of a solid material (e.g., an aluminium block).
核心原理 Key Principle:ΔE = m × c × Δθ,其中 c 为比热容,单位为 J/kg°C。通过电加热器提供已知能量,测量温度变化,即可计算 c 值。
实验步骤 Method:
- 测量铝块质量 m,记录于数据表。Measure the mass m of the aluminium block and record it.
- 将电加热器和温度计插入铝块专用孔中,用隔热材料包裹铝块以减少热量损失。Insert the electric heater and thermometer into the block's holes. Wrap the block in insulation to reduce heat loss.
- 记录初始温度 θ₁。Record the initial temperature θ₁.
- 接通电源,同时启动秒表。Switch on the power supply and start the stopwatch simultaneously.
- 每60秒记录一次电流 I、电压 V 和温度 θ,持续10分钟。Record current I, voltage V, and temperature θ every 60 seconds for 10 minutes.
- 计算每个时间段提供的能量:E = V × I × t。Calculate the energy supplied for each interval: E = V × I × t.
- 绘制温度-能量图表,斜率 = 1/(m×c),由此计算 c。Plot a graph of temperature against energy. The gradient = 1/(m×c), from which c can be determined.
变量分析 Variables:自变量为加热时间(或供给能量);因变量为温度变化;控制变量为铝块质量和加热器功率。
常见失分点 Common Pitfalls:未包裹隔热材料导致热量散失过多,实验值偏高;温度计未完全插入孔中导致读数不准;忘记测量并记录铝块质量。
考试技巧 Exam Tips:考试常问"为什么实验值比标准值大"——标准答案是热量散失到环境中。若问改进方法,答:使用更厚的隔热层、从低于室温开始加热到高于室温相同幅度以抵消热交换。
实验二:热绝缘研究 | RP2: Thermal Insulation (Triple Only)
实验目的 Aim:研究不同材料的隔热效果。Investigate the effectiveness of different materials as thermal insulators.
核心原理 Key Principle:隔热材料的有效性通过热量散失速率来衡量——温度下降越慢,隔热效果越好。The effectiveness of an insulator is measured by the rate of heat loss — the slower the temperature drops, the better the insulator.
实验步骤 Method:
- 准备相同大小的烧杯,分别用不同隔热材料(棉花、泡沫、气泡膜等)包裹。Prepare identical beakers and wrap each with a different insulating material (cotton wool, foam, bubble wrap, etc.).
- 每个烧杯倒入等量(如200ml)的热水(约80°C)。Pour the same volume (e.g., 200ml) of hot water (≈80°C) into each beaker.
- 用带温度计孔的硬纸板盖住杯口。Cover each beaker with a cardboard lid with a hole for the thermometer.
- 每30秒记录一次温度,持续20分钟。Record the temperature every 30 seconds for 20 minutes.
- 绘制所有材料的冷却曲线于同一坐标系中。Plot cooling curves for all materials on the same axes.
- 比较各曲线的下降速率,下降最慢者隔热效果最优。Compare the rate of temperature drop — the slowest drop indicates the best insulator.
变量分析 Variables:自变量为隔热材料类型;因变量为温度下降速率;控制变量为水的初始温度、水的体积、烧杯尺寸、环境温度。
常见失分点 Common Pitfalls:各烧杯初始水温不一致;杯口未盖导致蒸发散热差异;未设置无隔热对照组。
考试技巧 Exam Tips:务必包含对照组(无隔热包裹的烧杯)!这是评分关键点。图表题常要求计算某一时间段的温度变化速率。
实验三:导线电阻 | RP3: Resistance of a Wire
实验目的 Aim:研究导线长度如何影响其电阻。Investigate how the length of a wire affects its resistance.
核心原理 Key Principle:R = V/I(欧姆定律)。电阻与导线长度成正比:R ∝ L。当材料与横截面积相同时,越长电阻越大。
实验步骤 Method:
- 将电阻线(如康铜丝)拉直固定在米尺上。Attach the resistance wire (e.g., constantan) tautly along a metre ruler.
- 将一个鳄鱼夹固定在导线0cm端,另一个作为滑动触点。Connect one crocodile clip at the 0 cm end and use the other as a sliding contact.
- 连接电路:电源、安培计(串联)、伏特计(并联在导线两端)。Set up the circuit: power supply, ammeter (in series), voltmeter (in parallel across the wire).
- 从20cm开始,每次增加10cm,记录对应长度下的电流 I 和电压 V。Starting at 20 cm, record I and V for each length, increasing by 10 cm each time.
- 计算每个长度的电阻 R = V/I。Calculate resistance R = V/I for each length.
- 绘制电阻-长度图,应为过原点的直线。Plot a graph of resistance against length — it should be a straight line through the origin.
变量分析 Variables:自变量为导线长度;因变量为电阻;控制变量为导线材料、横截面积(同一条导线)、温度(保持低电流避免发热)。
常见失分点 Common Pitfalls:电流过大导致导线发热,电阻变化(温度效应);接触不良导致读数不稳定;从0cm开始导致电阻太小难以精确测量。
考试技巧 Exam Tips:必须从20-30cm开始测量,给导线足够长度以获得可测电阻值。考试可能问"为什么用低电流"——答:减少导线发热对电阻的影响。Why use a low current? To minimize heating of the wire, which would change its resistance.
实验四:I-V特性曲线 | RP4: I-V Characteristics
实验目的 Aim:测定电阻器、灯丝灯泡和二极管的电流-电压特性曲线。Determine the I-V characteristics of a resistor, a filament lamp, and a diode.
核心原理 Key Principle:不同元件的 I-V 曲线特征不同。电阻器:过原点的直线(欧姆导体);灯丝灯泡:S形曲线(温度升高电阻增大);二极管:正向导通反向截止。
实验步骤 Method:
- 依次将电阻器、灯泡、二极管接入电路。Connect each component (resistor, filament lamp, diode) to the circuit in turn.
- 电路含:可变电源、安培计(串联)、伏特计(并联在元件两端)。The circuit includes: variable power supply, ammeter (series), voltmeter (parallel across the component).
- 从0V开始逐步增加电压,记录每组 I-V 数据。Starting from 0V, gradually increase the voltage and record paired I-V readings.
- 对于二极管:先测正向(低电压范围0-2V),再测反向。For the diode: measure forward bias first (0-2V range), then reverse bias.
- 每个元件获取至少6组数据点。Obtain at least 6 data points for each component.
- 分别绘制 I-V 曲线。Plot I-V graphs for each component separately.
变量分析 Variables:自变量为电压(通过调节电源改变);因变量为电流;控制变量为环境温度、连接导线。
常见失分点 Common Pitfalls:二极管方向接反而无读数;灯泡电压过高烧毁;未包含反向偏置数据;混淆安培计和伏特计的接法(串联vs并联)。
考试技巧 Exam Tips:必考:解释灯泡曲线弯曲的原因——灯丝温度升高,离子振动加剧,电子流动阻力增大。The filament heats up, ions vibrate more vigorously, increasing resistance to electron flow. 二极管曲线在0.6-0.7V处"拐弯"是因为达到了硅的阈值电压。
实验五:密度测定 | RP5: Density
实验目的 Aim:测定规则固体、不规则固体和液体的密度。Determine the density of regular solids, irregular solids, and liquids.
核心原理 Key Principle:ρ = m/V。规则固体用尺量体积;不规则固体用排水法(阿基米德原理);液体用量筒直接读取体积。
实验步骤 Method:
规则固体 Regular Solid:
- 用电子天平测量质量 m。Measure mass m using an electronic balance.
- 用游标卡尺或千分尺测量尺寸(长宽高或直径),计算体积 V。Measure dimensions (length, width, height or diameter) with vernier calipers or a micrometer, then calculate volume V.
- 计算密度 ρ = m/V。Calculate density ρ = m/V.
不规则固体 Irregular Solid:
- 用天平测量质量。Measure mass with a balance.
- 在量筒中倒入适量水,记录初始体积 V₁。Pour water into a measuring cylinder, record initial volume V₁.
- 将固体用细线悬挂缓慢放入水中(完全浸没),记录新体积 V₂。Lower the solid into the water using a thin thread (fully submerged), record new volume V₂.
- 体积 V = V₂ - V₁。The volume V = V₂ - V₁.
- 计算密度。Calculate density.
液体 Liquid:
- 测量空量筒质量 m₁。Measure the mass of an empty measuring cylinder m₁.
- 倒入液体,读取体积 V。Pour in the liquid and read the volume V.
- 测量含液量筒总质量 m₂。Measure the total mass m₂ (cylinder + liquid).
- 液体质量 m = m₂ - m₁,密度 ρ = m/V。Mass of liquid m = m₂ - m₁, density ρ = m/V.
变量分析 Variables:因变量为密度;自变量为物体选择;不存在严格意义上的自变量(本实验是测定而非探究关系)。
常见失分点 Common Pitfalls:排水法时固体未完全浸没;读数时视线未与液面凹面底部齐平;忘记减去初始体积 V₁。
考试技巧 Exam Tips:考试可能要求解释为什么有些固体不适用排水法——答:会溶于水的物质(如盐、糖)或会浮在水面的物质(密度小于水)。For soluble or floating solids, use a different liquid or measure displacement with sand instead.
实验六:力和弹性 | RP6: Force and Extension (Hooke's Law)
实验目的 Aim:研究弹簧伸长量与所受力的关系。Investigate the relationship between force and extension for a spring.
核心原理 Key Principle:胡克定律 F = k × e,其中 k 为弹簧常数(N/m),e 为伸长量(m)。在弹性限度内,力与伸长量成正比。
实验步骤 Method:
- 将弹簧竖直悬挂在支架上,底部附指针。Suspend the spring vertically from a clamp stand with a pointer attached to its base.
- 在指针旁固定毫米刻度尺,记录无负载时的指针位置(原始长度)。Mount a millimetre ruler next to the pointer and record its position with no load (original length).
- 逐一添加砝码(如每次100g),每次记录指针位置。Add masses one at a time (e.g., 100g each time), recording the pointer position after each addition.
- 计算每次伸长量 e = 当前位置 - 原始位置。Calculate extension e = current position - original position for each load.
- 计算每个砝码的重力 F = mg(g = 9.8 N/kg)。Calculate the weight of each mass: F = mg (g = 9.8 N/kg).
- 绘制力-伸长量图,直线段斜率即为弹簧常数 k。Plot a graph of force against extension. The gradient of the straight-line portion gives the spring constant k.
变量分析 Variables:自变量为力(砝码重量);因变量为弹簧伸长量;控制变量为同一弹簧、环境温度。
常见失分点 Common Pitfalls:忘记测量并减去原始长度;超出弹性限度后仍当作线性数据处理;砝码单位混淆(克vs牛顿)。
考试技巧 Exam Tips:弹性限度判断:图上点偏离直线即为超过弹性限度。弹簧常数 k 的单位是 N/m,计算时伸长量必须换算为米。Beyond the limit of proportionality, the graph curves — this is where Hooke's Law no longer applies. 学生会常混淆"elastic limit"和"limit of proportionality",考试中两者可互换使用。
实验七:加速度与力 | RP7: Acceleration and Force
实验目的 Aim:研究力对物体加速度的影响(验证牛顿第二定律 F = ma)。Investigate the effect of force on the acceleration of an object (verify Newton's Second Law, F = ma).
核心原理 Key Principle:F = ma。保持系统总质量不变,改变加速力,测量加速度变化。
实验步骤 Method:
- 将小车放在水平轨道上,一端连接细绳绕过滑轮,末端挂砝码钩。Place a trolley on a horizontal track. Attach a string that runs over a pulley at the end, with a mass hanger on the other end.
- 在小车上固定一张卡片(用于光门计时)。Attach a card of known width to the trolley (for light gate timing).
- 在轨道上安置两个光门,测量它们之间的距离 s。Position two light gates on the track and measure the distance s between them.
- 在砝码钩上放一个砝码(如100g),将其他砝码放在小车上(保持系统总质量不变)。Place one mass (e.g., 100g) on the hanger and the remaining masses on the trolley (to keep total system mass constant).
- 释放小车,光门记录通过时间,计算初速度 u、末速度 v 和加速度 a = (v²-u²)/(2s)。Release the trolley. The light gates record transit times. Calculate u, v, and a = (v²-u²)/(2s).
- 每次将砝码钩上的一个砝码移到小车上(加速力增大的同时保持总质量不变),重复实验。Each time, transfer one mass from the trolley to the hanger (increasing the accelerating force while keeping total mass constant). Repeat.
- 绘制加速度-力图,应为过原点的直线。Plot acceleration against force — should be a straight line through the origin.
变量分析 Variables:自变量为加速力(砝码钩上的质量);因变量为加速度;控制变量为系统总质量(小车+所有砝码)。
常见失分点 Common Pitfalls:忘记将砝码从小车移到砝码钩上以保持总质量不变(这是本实验关键设计!);轨道未调水平导致重力分量影响;摩擦力未补偿。
考试技巧 Exam Tips:为什么要把砝码从小车移到钩上?答:保持整个加速系统的总质量不变,这样才能单独研究力对加速度的影响。This is the most frequently tested concept for this practical — explain why masses are transferred rather than added. 还可以用带滑轮的小车下坡法做本实验的变体版本。
实验八:水波波纹 | RP8: Ripple Tank (Waves)
实验目的 Aim:观察水波特性,测量波速、频率和波长。Observe water wave properties and measure wave speed, frequency, and wavelength.
核心原理 Key Principle:v = f × λ。通过波纹槽可以直观观察波的反射、折射和衍射现象。
实验步骤 Method:
- 在波纹槽中注入约5mm深的清水。Fill the ripple tank with water to a depth of about 5 mm.
- 将振动器(连接信号发生器)的dipper接触水面。Place the dipper of the vibrator (connected to a signal generator) so it just touches the water surface.
- 打开上方灯源,在下方白纸上观察波纹投影。Turn on the overhead lamp and observe the wave shadows on the white paper below.
- 设定信号发生器频率为20Hz,用尺子在投影上测量多个波长的总长度,除以波数得单波长 λ。Set the signal generator to 20 Hz. Measure the total length of several wavelengths on the shadow image, then divide by the number of waves to get λ.
- 记录频率 f(从信号发生器读取)。Record frequency f from the signal generator.
- 计算波速 v = f × λ。Calculate wave speed v = f × λ.
- 在槽中放置障碍物,观察衍射现象。Place barriers in the tank to observe diffraction.
变量分析 Variables:方法一(测波速):自变量为频率,因变量为波长,波速应为常数。方法二:可研究水深对波速的影响。
常见失分点 Common Pitfalls:水深不均匀导致波纹变形;灯源高度调节不当,投影模糊;测量波长时只量一个波(误差大),应量多个波取平均值。
考试技巧 Exam Tips:测多个波长再除以波数是标准技巧,考试中说明理由即可得分。Measure across 5-10 wavelengths and divide — this reduces percentage uncertainty. 衍射现象是高频考点:窄缝宽=波长时衍射最明显。
实验九:光的反射与折射 | RP9: Light (Reflection & Refraction)
实验目的 Aim:研究光在平面镜上的反射和光通过透明介质(玻璃)的折射。Investigate reflection of light by a plane mirror and refraction of light through a transparent block.
核心原理 Key Principle:反射定律(入射角=反射角);斯涅尔定律 n = sin i / sin r。
实验步骤 Method:
反射 Reflection:
- 在白纸上画一条直线,将平面镜沿此线垂直放置。Draw a straight line on white paper and place a plane mirror along it, standing vertically.
- 用射线盒发射一条细光束,以一定角度射向镜面。Use a ray box to shine a thin beam of light at the mirror at an angle.
- 用铅笔沿入射光线和反射光线画线标记。Mark the paths of the incident and reflected rays with a sharp pencil.
- 移开镜子,画法线(垂直于镜面的线),用量角器测量入射角 i 和反射角 r。Remove the mirror, draw the normal, and measure i and r with a protractor.
- 在10°至80°范围内重复多次。Repeat for a range of angles from 10° to 80°.
折射 Refraction:
- 将矩形玻璃块放在白纸上,沿轮廓画出边界。Place a rectangular glass block on white paper and trace its outline.
- 以一定角度射入光线,标记入射光线和出射光线。Shine a ray of light at an angle into the block, mark the incident and emergent rays.
- 移开玻璃块,连接入射点和出射点得到折射光线。Remove the block and join the points of incidence and emergence to get the refracted ray.
- 画法线,测量入射角 i 和折射角 r。Draw normals and measure i and r.
- 重复多次,计算 sin i / sin r 的平均值即为折射率 n。Repeat for multiple angles; the average of sin i / sin r gives the refractive index n.
变量分析 Variables:自变量为入射角 i;因变量为反射角 r 或折射角 r;控制变量为镜面位置、玻璃块材质。
常见失分点 Common Pitfalls:法线未画准确(必须真正垂直于镜面);铅笔线条太粗影响角度测量精度;光从玻璃射入空气时发生全内反射导致看不到出射光线。
考试技巧 Exam Tips:本实验高频考试题型:解释为什么出射光线与入射光线平行——因为玻璃块两面平行,光线在两界面各折射一次后方向恢复。The emergent ray is parallel to the incident ray because the two faces of the block are parallel — the ray is refracted twice in opposite directions. 用 sin i-sin r 图的斜率可以直接得到折射率。
实验十:热辐射与吸收 | RP10: Radiation and Absorption
实验目的 Aim:研究不同表面(哑光黑和亮银色)对红外辐射的吸收和发射能力。Investigate how the nature of a surface affects its absorption and emission of infrared radiation.
核心原理 Key Principle:哑光黑色表面是良好的热辐射吸收体和发射体;光亮银色表面是差吸收体和差发射体(但为良好反射体)。Matte black surfaces are good absorbers and emitters; shiny silver surfaces are poor absorbers and emitters (but good reflectors).
实验步骤 Method:
- 准备Leslie立方体(四面分别为哑光黑、哑光白、亮银、裸金属)。Prepare a Leslie cube with four faces: matte black, matte white, shiny silver, and bare metal.
- 向Leslie立方体中倒入沸水(约100°C),盖紧盖子。Fill the Leslie cube with boiling water (≈100°C) and seal the lid.
- 用红外探测器依次测量每个表面正前方固定距离处的红外辐射强度。Use an infrared detector to measure the radiation intensity at a fixed distance from each surface in turn.
- 记录每个表面的读数。Record the reading for each surface.
- 对于吸收实验:用红外灯照射两个相同烧瓶(一个涂黑一个涂银),内含等量水并插温度计,记录每30秒温度变化。For absorption: use an infrared lamp to heat two identical flasks (one painted black, one silver) containing equal water with thermometers. Record temperature every 30 seconds.
变量分析 Variables:自变量为表面颜色/材质;因变量为红外辐射强度(发射实验)或温度上升速率(吸收实验);控制变量为与探测器的距离、水温、环境条件。
常见失分点 Common Pitfalls:探测距离不一致导致数据不可比;Leslie立方体未盖紧导致热量通过对流散失;发射实验中未等温度稳定就读数。
考试技巧 Exam Tips:经典考点:为什么黑色表面夏天吸热多冬天散热快?答:黑色既是良好吸收体也是良好发射体。Why do marathon runners wear silver blankets? The shiny surface reflects body heat back and is a poor emitter, keeping the runner warm. Leslie立方体是高频考点——记住四面排名:哑光黑>哑光白>裸金属>亮银。
十个实验总结 | Summary of All 10 Practicals
RP1 比热容 Specific Heat Capacity — 核心公式:ΔE = mcΔθ | 常见失分:未隔热,热量散失
RP2 热绝缘 Thermal Insulation — 核心公式:冷却速率比较 | 常见失分:缺少对照组
RP3 导线电阻 Resistance — 核心公式:R = V/I | 常见失分:电流过大导线发热
RP4 I-V特性 I-V Characteristics — 核心公式:R = V/I | 常见失分:混淆仪表接法
RP5 密度 Density — 核心公式:ρ = m/V | 常见失分:排水法固体未全浸
RP6 力与弹性 Force & Extension — 核心公式:F = ke | 常见失分:未减原始长度
RP7 加速度 Acceleration — 核心公式:F = ma | 常见失分:未保持总质量不变
RP8 水波 Ripple Tank — 核心公式:v = fλ | 常见失分:只测单个波长
RP9 光 Light — 核心公式:n = sin i/sin r | 常见失分:法线不垂直
RP10 热辐射 Radiation — 核心公式:表面特性 | 常见失分:探测距离不一致
考试高分策略 | Exam Tips for Top Marks
1. 变量识别 Variable Identification:实验题中"identify the independent/dependent/control variables"几乎必考。只要记住:自变量=你主动改变的量,因变量=你测量的结果,控制变量=保持不变的量。
2. 安全措施 Safety Precautions:涉及热水的实验(RP1、RP2、RP10)必须提防烫伤;涉及重物的实验(RP6、RP7)提防砸脚;电气实验(RP3、RP4)提防短路和触电。
3. 精度改进 Improving Accuracy:重复实验取平均值、使用更精密的仪器(如用数字温度计代替水银温度计)、测量多个周期取平均值(如RP8测多个波长)。
4. 图表题 Graph Questions:必须会:选择合适比例尺使图占满2/3以上坐标纸面积;用X标记数据点(不用点);画出最佳拟合线;计算斜率时用大三角形取点。
5. 误差来源 Sources of Error:区分系统误差(如仪器零点误差)和随机误差(如读数视差)。随机误差取平均值可减小,系统误差需校准仪器。
联系我们 | Contact Us
正在备考GCSE/IGCSE物理?需要专业老师一对一辅导实验操作?我们的A-Level/GCS物理名师团队覆盖全部10个必做实验的实操训练。欢迎联系咨询:
Preparing for GCSE/IGCSE Physics? Need one-to-one tutoring on practical experiments? Our team of A-Level/GCSE Physics specialists covers hands-on training for all 10 required practicals. Get in touch:
免费咨询 Free Consultation
16621398022
电话同微信 | Phone & WeChat
aleveler.com© 2026 EasyUKExam · A-Level & GCSE Specialist · 专注英国课程辅导
更多咨询请联系16621398022(同微信)

或截图后用「扫一扫 → 相册」选择本图