Practical questions
You will complete eight required practical activities if you are studying GCSE Physics and 21 if you are studying GCSE Combined Science.
There will be a number of different types of practical based questions. Some will be on the set required practicals, some will cover the working scientifically terms and some will be on other science practicals which you might have done in class. Use all the information given in the question particularly any diagrams to help you understand what the question is about.
This page contains AQA material which is reproduced by permission of AQA.
Learn about practicals with Dr Alex Lathbridge
Listen to the full series on 大象传媒 Sounds.
Dr Alex Lathbridge answers questions about practicals.
Sample question 1 - Foundation/ Higher
Question
The data given in the table below was obtained from an investigation into the refraction of light at an air to glass boundary.
| Angle of incidence (掳) | Angle of refraction (掳) |
| 20 | 13 |
| 30 | 19 |
| 40 | 25 |
| 50 | 30 |
| Angle of incidence (掳) | 20 |
|---|---|
| Angle of refraction (掳) | 13 |
| Angle of incidence (掳) | 30 |
|---|---|
| Angle of refraction (掳) | 19 |
| Angle of incidence (掳) | 40 |
|---|---|
| Angle of refraction (掳) | 25 |
| Angle of incidence (掳) | 50 |
|---|---|
| Angle of refraction (掳) | 30 |
Describe an investigation a student could complete in order to obtain similar data to that given in the table above.
Your answer should consider any cause of inaccuracy in the data.
A labelled diagram may be drawn as part of your answer. [6 marks]
You will need to describe a full method for an investigation. Steps should be logically ordered so that they could be followed by someone else to obtain valid results. You should look to include the following ideas:
- place a glass block on a piece of paper
- draw around the glass block and then remove from the paper
- draw a line at 90掳 to one side of the block (the normal)
- use a protractor to measure and then draw a line at an angle of 20掳 to the normal
- replace the glass block
- using a ray box and slit, point the ray of light down the drawn line
- mark the ray of light emerging from the block
- remove the block and draw in the refracted ray
- measure the angle of refraction with a protractor
- repeat the procedure for a range of values of the angle of incidence
Possible source of inaccuracy - the width of the light ray which makes it difficult to judge where the centre of the ray is
Sample question 2 - Foundation/Higher
Question
A student investigated how the magnification produced by a convex lens varies with the distance (d) between the object and the lens.
The student used the apparatus shown in Figure 1.
Figure 1
The student measured the magnification produced by the lens by measuring the image height in centimeters.
The data recorded by the student is given in Table 2.
Table 2
| Distance between the object and the lens (cm) | Magnification |
| 25 | 4.0 |
| 30 | 2.0 |
| 40 | 1.0 |
| 50 | 0.7 |
| 60 | 0.5 |
| Distance between the object and the lens (cm) | 25 |
|---|---|
| Magnification | 4.0 |
| Distance between the object and the lens (cm) | 30 |
|---|---|
| Magnification | 2.0 |
| Distance between the object and the lens (cm) | 40 |
|---|---|
| Magnification | 1.0 |
| Distance between the object and the lens (cm) | 50 |
|---|---|
| Magnification | 0.7 |
| Distance between the object and the lens (cm) | 60 |
|---|---|
| Magnification | 0.5 |
It would be difficult to obtain accurate magnification values for distances greater than 60 cm.
Suggest one change that could be made so that accurate magnification values could be obtained for distances greater than 60 cm. [1 mark]
This question is not based on any of the eight required practical experiments set by AQA.
Answers include:
- use a taller object
- use a microscope
- attach a scale to the screen and use a magnifying glass
A working solution would either make the image larger or allow the student to see the smaller image more clearly.