Measurements are always uncertain: there is no such thing as a perfectly precise measurement. At the very least, the instrument used will limit the precision of the value but in many cases other factors can introduce even greater variability. It is always the greater of these two numbers (the resolution of the instrument and variability … Continue reading Uncertainties and Error Bars
Revision tips for Paper 3A
It’s a fool’s game to try to predict what will be in an examination paper but… looking back over past years, there are three practicals that have been used very little in Paper 3A and one of those hasn’t appeared since 2020. So, in my opinion, there is a good chance that this year’s paper … Continue reading Revision tips for Paper 3A
How to read Vernier callipers
Having previously discussed micrometers as instruments that some people find tricky to read (see https://physbang.com/2025/04/09/how-to-read-a-micrometer/) we now come to the instrument that many people find even more difficult; Vernier callipers. Whereas micrometers are mostly used for measuring thicknesses between flat surfaces, callipers are better when the surfaces are curved. In particular, callipers are commonly used … Continue reading How to read Vernier callipers
Random and Systematic Errors
Two previous posts covered uncertainties in the context of thermal energy transfers but now we need to consider random and systematic errors as they apply more generally in the current AQA A-Level Physics course. NOTE: The AQA A-Level Physics syllabus takes a simplified approach to uncertainties so if you are doing independent revision you may … Continue reading Random and Systematic Errors
How to read a micrometer
Being able to take measurements using common items of instrumentation is an expected skill for A-Level Physics and can be tested in examinations using diagrams or photographs. This post is the first in a short series that will look at measurement skills, starting with a piece of equipment that often causes difficulties; the micrometer. To … Continue reading How to read a micrometer
Paper 3a, Q3 walk-through
This post completes an explanation given to my current Y13 students, which was unfinished at the end of our lesson. It relates to the second half of Q3 in Paper 3a for the AQA A-Level Physics examination of June 2023. You can download a copy of the complete paper here. To solve Q3.4 you must … Continue reading Paper 3a, Q3 walk-through
Effective Revision
The following information is specifically for the benefit of my students who are studying the AQA A-Level Physics course, 7408, for examination this summer (2025). That said, the principles of revision are well known and apply much the same to every subject at every level. With that in mind, here are my top six tips. … Continue reading Effective Revision
How to Use Logarithms
Although they can seem confusing at first sight, logarithms are just mathematical functions that allow calculations to be carried out quicker than would otherwise be the case. So although they may seen daunting, you should think of logarithms as a way to make calculations easier – once you have mastered the rules. There is quite a … Continue reading How to Use Logarithms
Half-term Revision: Forces and Paper 2
Last year (2022) I created two sets of questions that are designed to test your knowledge of the Forces and their Interactions topic for Paper 2 of AQA Trilogy Physics. One test is for Higher Tier and can be accessed by clicking here; the other is for Foundation Tier and can be accessed here. Both … Continue reading Half-term Revision: Forces and Paper 2
Key Facts: Electric circuits
Electricity is one of the forms of energy transfer so it is not surprising that the definition of the volt (the unit for measuring potential difference) is the energy carried per unit charge. In symbols, where Q is the symbol for charge, this relationship is written as; V = E / Q It is important … Continue reading Key Facts: Electric circuits
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