AQA A-Level Physics Unit 3 Mark Scheme: January 2020 | AQA A-level 物理 Unit 3 评分方案解析：2020年1月

📚 AQA A-Level Physics Unit 3 Mark Scheme: January 2020 | AQA A-level 物理 Unit 3 评分方案解析：2020年1月

The January 2020 series of AQA A-level Physics Unit 3 (7408/3) tested much more than factual recall. This paper rewards practical competence: the ability to read instruments correctly, to record data honestly, to analyse a graph with judgement and to evaluate a method with insight. Understanding the mark scheme is half the battle. In this guide, we will break down exactly where marks are awarded, what examiners’ annotations mean and how you can convert your practical knowledge into maximum marks.

AQA A-level 物理 Unit 3（7408/3）2020年1月考试所考查的远不止知识背诵。本卷旨在奖励真正的实验能力：正确读数、如实记录数据、有理有据地分析图像、并运用洞察力评估实验方法。理解评分方案等于成功了一半。本指南将逐项拆解得分点的分布、考官批注的含义，以及如何将你的实验知识转化为最高分。

1. Paper 3 Structure | 试卷3结构与分值

Unit 3 (7408/3) is divided into two sections. Section A carries about 45 marks and consists of compulsory short-answer questions on practical skills and data analysis. Section B carries about 35 marks and covers one option topic: Astrophysics, Medical physics, Engineering physics, Turning points in physics or Electronics. In the January 2020 session, candidates who had prepared the same option as their teachers expected still needed to manage the clock carefully, because Section A contains many small calculation steps that each carry discrete marks.

Unit 3（7408/3）试卷分为两大部分。A部分约45分，为实验技能与数据分析的必做简答题；B部分约35分，考查一个选修专题：天体物理、医学物理、工程物理、物理学的转折点或电子学。在2020年1月考试中，即使考生所准备的选项与教师预期一致，仍需谨慎管理时间，因为A部分包含大量小而分散的计算步骤，每个步骤都单独计分。

A useful habit is to read the option section first when the examination begins. Because Section A requires sustained concentration, many candidates attempt Section B first to secure the topic-based marks while their memory of definitions is still fresh. The mark scheme shows that Section B short answers rarely require extended essays, so precise key phrases are worth more than long descriptive paragraphs.

一个实用习惯是考试开始后先读B部分。由于A部分需要持续高度专注，许多考生会先做B部分，趁定义记忆清晰时先拿下专题分。评分方案显示，B部分的简答题很少需要长篇大论，精确的关键短语远比冗长的描述段落更有价值。

2. Command Words and What They Demand | 指令词及其隐含要求

The mark scheme is built around specific command words. Each command word tells you exactly what the examiner will credit. Writing an explanation when a one-word answer is required does not earn extra marks; conversely, giving only a final number when a ‘calculate’ question asks you to show working can lose method marks.

评分方案围绕特定的指令词构建。每个指令词都在告诉你考官会认可什么。当题目只需要一个词语时，写一大段解释并不会加分；反之，当”计算”题要求写出过程时，只给一个最终数字可能会失去方法分。