Practical questions
During the GCSE Physics course you will complete practical activities from eight Practical Activity Groups (PAGs).
The exams will include questions about the apparatus, methods, safety precautions, results, analysis and evaluation of some of these experiments. You may also be asked to apply your knowledge to unfamiliar practical contexts, which will draw on your practical knowledge and understanding.
Practical questions will appear throughout both exam papers (Breadth and Depth), and at both Foundation tier and Higher tier.
Remember to look at your lab book or your notes from the practical activities you have done when you're revising for the exams.
The practical questions also test your knowledge of 'Ideas about Science'.
There are four main aspects to 'Ideas about Science'. These are:
- Planning practical experiments and investigations (including writing hypotheses and predictions, selecting apparatus and describing methods, controlling factors, and working safely)
- Processing and analysing data (including doing calculations, presenting data graphically, identifying patterns and trends, evaluating results and experiments, and interpreting data to draw appropriate conclusions)
- Developing scientific explanations (including ideas about correlation and cause, peer review, and the use of models in science)
- The impacts of applications of science (including positive and negative impacts on people, other organisms and the environment, and ideas about risk and ethics)
Learn about practicals with Dr Alex Lathbridge
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Dr Alex Lathbridge answers questions about practicals.
Sample question 1 - Higher
Question
Richard uses the equipment below to calculate the specific heat capacity of water.
a) State one safety issue Richard needs to consider in a risk assessment and explain what he can do to prevent this risk. [2 marks]
b) State and explain how he could improve the experiment to get a more accurate result. [2 marks]
OCR 21st Century Science, GCE Physics, Paper J259, 2016 - Higher.
a) Risk of burning from hot water/heating element. [1]
Prevent risk by using care when around hot water/putting lid on the beaker/putting heating element in the water before turning it on and waiting for it to cool before removing it. [1]
The first step in answering this question is to identify one of the risks involved in the experiment, and the obvious risk is the risk of burns from the hot water. The second part is to discuss how this risk can be reduced. Any sensible suggestion of a risk and the prevention will get you the two marks.
b) Any reference to insulation/lagging [1] as this reduces heat transfer to the surroundings. [1]
The important thing in this question is to look at the two command words - these are 'state' and 'explain'. If you just state that insulation will improve the accuracy of the experiment you will only get one mark. The second mark is given for explaining how this will make the results more accurate.
Sample question 2 - Higher
Question
Two students are investigating springs and forces.
They begin by comparing three different springs.
They measured how much each spring stretched for a range of different weights attached.
Here are their results:
| Force (N) in spring A | Extension (cm) in spring A | Force (N) in spring B | Extension (cm) in spring B | Force (N) in spring C | Extension (cm) in spring C |
| 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| 1.0 | 0.7 | 1.0 | 0.6 | 1.0 | 1.6 |
| 2.0 | 1.4 | 2.0 | 1.0 | 2.0 | 3.2 |
| 3.0 | 2.1 | 3.0 | 1.6 | 3.0 | 4.8 |
| 4.0 | 2.8 | 4.0 | 2.4 | 4.0 | 6.4 |
| 5.0 | 3.5 | 5.0 | 3.8 | 5.0 | 8.0 |
| Force (N) in spring A | 0.0 |
|---|---|
| Extension (cm) in spring A | 0.0 |
| Force (N) in spring B | 0.0 |
| Extension (cm) in spring B | 0.0 |
| Force (N) in spring C | 0.0 |
| Extension (cm) in spring C | 0.0 |
| Force (N) in spring A | 1.0 |
|---|---|
| Extension (cm) in spring A | 0.7 |
| Force (N) in spring B | 1.0 |
| Extension (cm) in spring B | 0.6 |
| Force (N) in spring C | 1.0 |
| Extension (cm) in spring C | 1.6 |
| Force (N) in spring A | 2.0 |
|---|---|
| Extension (cm) in spring A | 1.4 |
| Force (N) in spring B | 2.0 |
| Extension (cm) in spring B | 1.0 |
| Force (N) in spring C | 2.0 |
| Extension (cm) in spring C | 3.2 |
| Force (N) in spring A | 3.0 |
|---|---|
| Extension (cm) in spring A | 2.1 |
| Force (N) in spring B | 3.0 |
| Extension (cm) in spring B | 1.6 |
| Force (N) in spring C | 3.0 |
| Extension (cm) in spring C | 4.8 |
| Force (N) in spring A | 4.0 |
|---|---|
| Extension (cm) in spring A | 2.8 |
| Force (N) in spring B | 4.0 |
| Extension (cm) in spring B | 2.4 |
| Force (N) in spring C | 4.0 |
| Extension (cm) in spring C | 6.4 |
| Force (N) in spring A | 5.0 |
|---|---|
| Extension (cm) in spring A | 3.5 |
| Force (N) in spring B | 5.0 |
| Extension (cm) in spring B | 3.8 |
| Force (N) in spring C | 5.0 |
| Extension (cm) in spring C | 8.0 |
One of the students makes a comment about the data. "The data for all of the springs follows a linear relationship."
Is this student correct?
Use your understanding of what is meant by a linear relationship to help explain your answer. [2 marks]
OCR 21st Century Science, GCE Physics, Paper J259, 2016 - Higher.
The student is partly correct. Springs A and C follow a linear relationship but spring B does not [1]. In a linear relationship, the extension increases in equal amounts as the force increases [1].
If you look at the data given in this question you will see that in Spring A the extension increases by 0.7 cm with every newton of force added. In Spring C the extension increases by 1.6 cm with every newton added. Spring B does not increase in equal increments so therefore it does not show a linear relationship. A graph of extension against force would be a straight line for a linear relationship.
Sample question 3 - Foundation
Question
a) Which instrument, A, B C or D could be used to determine the volume of an irregular shaped solid? [1 mark]
b) How would you use it to find the volume? [3 marks]
OCR 21st Century Science, GCE Physics, PAG, February 2017.
a) C [1]
A measuring cylinder would be used to find the volume of an irregular shaped object.
b) Part fill the measuring cylinder with water and record the volume [1]. Carefully place the irregular shaped object into the water and record the new volume value [1]. The difference between these two values is the volume of the object [1].
You should have participated in doing this experiment in class. Recall the procedure used to find the volume of the irregular shaped object and write the instructions down in as much detail as possible.