Literacy in Advanced Higher Physics
The following terms may appear in questions in the Advanced Higher Physics exam. A brief explanation is provided which will help you understand what you have to do when you see these terms appear.
Identify, name, give, or state
Usually worth one mark, an explanation of your answer is not required. State questions are often State what is meant by which have a precise definition.
Describe
You must provide a statement or structure of characteristics and/or features.
Explain
You need to provide details as to how something works or reasons as to why something is happening. You should relate the cause and effect and/or make the relationships between things clear. You should use directly relevant and correct physics. Sometimes this question will also include a phrase like “explain in terms of…” it is therefore vital that your explanation includes the words/terms mentioned.
Determine / Calculate
Your answer will be a numerical value with unit, calculated from given facts, figures or information usually awarded three marks. The first mark for selecting the correct formula, the second mark for correct substitutions and the third mark for the final answer with unit to an appropriate number of significant figures, correctly rounded. The number of significant figures should be the same as the least precise numerical data given in the question. The final mark will not be awarded if the answer has more than two more or fewer than one less than the correct number of significant figures. Do not copy down answers from your calculator that contain a large number of significant figures or use ellipses. Do not round values at an intermediate stage, use the unrounded number in your calculator. Do not copy down answers from your calculator that contain a large number of significant figures or use ellipses.
Sometimes a calculate question has more than three marks with a mark awarded for another calculation or for selecting a value(s) from a table or graph or analysing results of an experiment or previous calculation.
Estimate
Your answer is an approximate value for something. This estimate may be based upon a calculation, from a graph or be estimated by comparison to a previous response.
Justify
This term will often appear as a follow up to a state question. Here you must provide a reason for the statement/suggestion/conclusion you provided. This might be by identifying an appropriate relationship and the effect of changing variables. You can justify using a calculation but remember to also state your conclusion.
Must Justify
You must not only state or select the correct response, but also provide supporting justification to achieve any marks. If you provide no reason, then even if you have the correct statement you will receive no marks.
Show that
You should “show” a particular answer is correct, you must start your response with an appropriate relationship, show the correct substitutions, and end with the final answer as it is shown, including the correct unit, to obtain all the marks available. If you do not start with showing the correct relationship, there will be 0 marks, these are usually two-mark questions.
Predict
You must suggest what may happen based upon available information. This will involve some comparison of data and will often require you to get your answer by analysing a graph, a table or a set of results.
Suggest how/why
This is like an explain question, but is about applying knowledge and understanding to a new situation. Often it relates to providing a possible improvement to an experiment or a reason for why something hasn’t worked as well as it should. Often several responses are acceptable: marks will be awarded for any suggestions that are supported by knowledge and understanding of physics. Be aware if you put more than one response any incorrect one will prevent a mark for a correct one.
Using your knowledge of Physics, comment on…
These are known as open-ended questions as they can have a range of different answers. You should make statements of relevant and correct physics at Advanced Higher Level. You can do this by providing explanations, calculations, justifications, suggestions and even drawings…… You will gain credit for the breadth and/or depth of your answer. You should answer in sentences and not in bullet points and making sure you refer to the question asked.
Draw
You need to draw something, it could be anything, but often a graph or line on a graph or circuit diagram etc. It is essential to use a ruler unless you are intentionally drawing a curve.
Compare
You will probably need to provide some numerical working as evidence for your final answer and compare it to another value (calculated or given).
Other language :
Reliability
A reliable experiment is one that is a fair test. Reliability is a measure of how dependably the data is from an experiment. Outwith the SQA some prefer the use of repeatability and reproducibility rather than reliability, at the moment SQA prefer reliability.
Repeatability is defined by the National Physical Laboratory as closeness of the agreement between repeated measurements of the same property under the same conditions.
Reproducibility as the closeness of the agreement between measurements of the same property carried out under changed conditions of measurement (e.g. by a different operator or a different method, or at a different time).
At Advanced Higher repeated measurements should always be taken, usually there should be at least three repeats and often five, sometimes more. The number of repeats required will depend upon the variation in the readings measured and the random uncertainty calculated as well as the time available to collect the data. If the random uncertainty is small or not significant then further repeats would not improve the reliability of the experiment.
An experiment could also be made more reliable from an increase in the range of the variable you are changing.
Sometimes a change the setup of the experiment can make it more reliable by reducing the systematic uncertainty and the adequacy of control of variables. Systematic uncertainty occurs when readings taken are either all too small or all too large. This can arise due to faulty measurement techniques or experimental design.
Precision
The uncertainty (scale reading and/or calibration) in a measurement gives an indication of the precision of the measurement. Precision can be improved by using different equipment, for example a ruler that only has a centimetre scale is less precise than a ruler that has a millimetre scale. This means the measurement will have a smaller scale reading uncertainty.
Precision can also mean how close a calculated value is to the expected value. For example an experiment to calculate the resistance of a resistor by Ohm’s law (by measuring current and voltage) might calculate a value of 11·0 ohms. This can be compared to the expected value from the supplier of 10·0 ohms.
An imprecise value would have a greater absolute uncertainty whereas a precise value would have a very small overall absolute uncertainty.
If a value is determined from a point on a graph, a more precise value from a graph might be achieved by more readings across the range or about a particular value.
Accuracy
Accuracy is the degree to which a measurement represents the true/actual value of something. Simply put: How close a measurement is to the true value?
An accurate measuring instrument, say a thermometer, is one whose readings confirm a known result.
A calibration uncertainty arises when there is a difference between a manufacturer’s claims for the accuracy of an instrument when compared with an approved standard.
In a diffraction experiment the distance from the grating to the screen might be increased to increase the separation of the fringes (maxima) as an increased separation can be measured more accurately.
Examples
Example 1 :
Identify 2017 – Section 2 – Question 6 (a)
Answer :
Acceptable answers would be:
Additional Guidance :
An arrow on the diagram could also get the marks however the direction must be correct (upwards).
Example 2 :
State - 2017 – Section 2 – Question 1 (a) (i) and 7 (c) (i)
Additional Guidance :
Also acceptable would be
Example 3 :
Describe 2019 – Section 2 – Question 9 (b)
Example 4 :
Show - 2017 – Section 2 – Question 12 b (i)
Example 5 :
Determine and Justify – 2016 - Section 2 - Q4 (a) and (b)
Example 6 :
Must Justify 2019 Section 2 Q 11 (c)
Additional Guidance :
More with no justification 0 marks.
More with incorrect justification 1 mark
Example 7 :
Explain – 2016 – Section 2 - Q 12 (b)
Additional Guidance
The underlined terms are important – it is difficult to get the marks without using them correctly. Any wrong physics then zero marks. Conduction or valence bands must be mentioned first, or zero marks as the physics would be wrong.
Example 8 :
Explain in terms 2017 – Section 2 – Q10 (a)
Example 9 :
Determine (non-calculation type) - 2016 – Section 2 - 8(d)
Answer :
Up the Page
Additional Guidance :
Example 10 :
Suggest 2019 – Section 2 Q 13 (c)
Example 11 :
Compare - 2017 – Section 2 – Question 5 (a)
Additional Guidance :
There are a variety of ways of correctly calculating this. See official marking scheme for all of them. If you state “greater” or “smaller” on its own, then 0 marks are awarded.
