Unit 6: Experimental Physics and Measurement Uncertainty | 第6单元：实验物理与测量不确定度

📚 Unit 6: Experimental Physics and Measurement Uncertainty | 第6单元：实验物理与测量不确定度

Unit 6 is the practical and experimental paper in many A-level Physics specifications. It tests not only whether you can recall physical theory, but also whether you can take measurements, estimate uncertainties, plot graphs, and evaluate a procedure critically. This article covers the core skills for Unit 6.

第6单元是许多 A-level 物理课程中的实验与操作考查部分。它不仅考察你是否能回忆物理理论，还考察你能否进行测量、估算不确定度、绘制图像并批判性地评价实验方案。本文涵盖第6单元的核心技能。

1. Understanding the Structure of Unit 6 | 理解第6单元的结构

In Unit 6, exam questions are usually based on familiar practical tasks such as measuring g by free fall, investigating springs, building circuits, or observing standing waves. You need to describe apparatus, identify independent and dependent variables, state control variables, calculate results, and comment on reliability.

在第6单元中，考试题通常基于熟悉的实验任务，例如通过自由落体测量 g、研究弹簧、搭建电路或观察驻波。你需要描述仪器、确定自变量和因变量、说明控制变量、计算结果并评价可靠性。

The paper often asks you to plan a method or improve an existing method. Therefore, you should learn a set of standard techniques rather than memorising individual experiments word for word.

试卷常要求你设计一种方法或改进现有方法。因此，你应该掌握一套标准实验技术，而不是逐字记住个别实验。

2. Instruments, Resolution and Single-Reading Uncertainty | 仪器、分辨率与单次读数不确定度

Every instrument has a resolution: the smallest change it can display. For a metre ruler the resolution is 1 mm, for a digital voltmeter it is the last digit. In many specifications the uncertainty in a single reading is taken as half the resolution, but for a digital reading it is usually ± the last digit.

每种仪器都有一个分辨率：即它能显示的最小变化。米尺的分辨率为 1 mm，数字电压表的分辨率是最后一位数字。在许多考试大纲中，单次读数的不确定度取分辨率的一半，但对于数字读数通常取最后一位数字的 ±1。

single-reading uncertainty = ± (resolution / 2)

For a stopwatch, the dominant uncertainty is usually your reaction time, not the display resolution. Reaction time is typically about 0.1 s to 0.3 s, so taking a single time measurement is much less reliable than timing several oscillations.

对于

Published by TutorHao | Exam Prep Revision Series | aleveler.com

更多咨询请联系16621398022（同微信）