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Hello guys, I know many of you will be sitting for this paper next week and are probably wondering how to revise, so I have compiled a few tips and notes for all of you. Enjoy!
1. During the test, read the question and all information given carefully. Make sure that you understand the experiment given. Certain parts of the question require you to record the readings from the experiment in a table. You should draw the tables before carrying out the experiment so that you can record your readings in the table straight away during the experiment. Then, carry out the experiment by following the steps given in the question exactly. You need to apply your Physics practical skills when carrying out the experiment.
2. Do not panic if the context of the practical experiment appears unfamiliar. Where appropriate, the question paper will tell you exactly what to do and how to do it.
3. If you find yourself in real difficulty setting up your practical equipment you may askyour supervisor for help, although you may lose one or more marks for this.
4. When recording readings from an measuring instrument (except metre rule, vernier calipers and micrometre screw gauge), the number of decimal places used should be equal to half of the smallest division of scale of the instrument (For example, if the instrument's smallest division of scale is 0.1, you should record the reading to the nearest 0.05, which is 2 decimal places.) For digital instruments (except digital stopwatch), the number of decimal places used should be the same as that shown on the display. The reading should be recorded to the nearest 0.1cm for metre rule, 0.01cm for vernier calipers, 0.01mm for micrometer screw gauge and 0.1s for stopwatch (both analogue and digital). In all cases, do not give more or less number of decimal places. You must also write the correct units.
5. To save time, draw a single table for your results before taking any readings and enter your readings in the table as you take them (so that you do not waste time having to copy them later).
6. In most cases, you should take each reading twice, then calculate and record the mean of the 2 readings. Some questions are worth 2 marks, which means you get one mark for repeating. Ensure that you show in your answer both readings and the calculation of their mean. However, for the part in Question 1 which requires you to record readings in a table, questions that carry only 1 mark and questions which state that repeated readings are not required, you only need to take each reading once and record it straight away.
7. All the raw readings of a particular quantity should be recorded to the same number of decimal places which should in turn be consistent with the uncertainty in the readings. Each column heading in your table must contain both a quantity and its unit. For instance, if you have measured time “t” in seconds, your column heading would bewritten as “t/s”.
5. When plotting a graph, draw both the horizontal and vertical axis on the graph paper correctly. Label both axis correctly and state the unit (if any). Use a suitable scale for both axis and do not use any odd scales such as 3:10. Both the x-axis and y-axis need not start from 0. The scales should be chosen such that the points plotted on graph cover at least half of the graph paper. The markings on the scales should not be more than 3 large squares apart. Plot all points on the graph accurately. The points should be accurate to half a small square. For all the points, their diameter should not be larger than half a small square. Then, draw the correct straight line or curve. When drawing the straight line or curve, it should pass through all points on the graph if possible. If this is not possible, the line or curve should pass through as many points on the graph as possible, all the points should be close to it and the number of points above and below the line or curve should be almost equal.
6. When determining the gradient of the line of graph, choose 2 points on the line and draw a triangle. The distance between the 2 points chosen should be at least half the length of the line. When determining the y-intercept of the line of graph, if the x-axis starts from 0, you can read it off directly from the y-axis of graph, or if the x-axis does not start from 0, you should choose a point on the line, preferably one of the points that you used to calculate its gradient, and substitute its x and y values as well as the gradient into the equation y=mx+c to determine the value of c which is the y-intercept.
7. For any questions involving calculation, the number of significant figures of your answer should be equal to or one more than the number of significant figures of the raw value used in the calculation with the least number of significant figures. You should show all workings and do not skip any important steps. You must also write the correct unit for the final answer if it is not provided. You are not allowed to write extra solutions or answers. If you do so and any of the answers or solutions is wrong, marks will be deducted. For a calculation question which requires you to use your answer from the previous question, even if your answer for the previous question is wrong and you use it for this question causing your answer for this question to be wrong, usually you will still get full marks for this question as long as your calculation for this question is correct. This is known as 'error carried forward'.
8. For the part of Question 2 which asks you to estimate the percentage uncertainty in a particular value, in most cases the absolute uncertainty used to calculate the percentage uncertainty should be equal to twice the smallest division of scale of the instrument used to measure the value (For both analogue and digital stopwatch, the absolute uncertainty used should be 0.2s). This is because the measurement for this part is often difficult to be done accurately.
9. For the part of Question 2 which asks you whether your results support the suggested relationship between 2 variables, you have to calculate the percentage difference between 2 values of a constant which is obtained in previous part of the question. The suggested relationship is supported if the percentage difference is 5% or less and not supported if the percentage difference is more than 5%. The percentage difference is equivalent to the difference of the two values divided by the largest value.
10. For all questions, you should use the correct experimental and Physics terms in your answer. Do not replace them with other terms that are inappropriate, even if their meaning are the same. You should spell all experimental and Physics terms correctly. If you can't do so, try to spell it in such a way where it sounds the same as the actual term when read out. Marks are usually not deducted for spelling errors in experimental and Physics terms as long as it still sounds the same and that it is not easily confused with other terms. If you spell other terms wrongly or if you make grammatical errors in your answer, marks will not be deducted for as long as the examiner can understand what you are writing. You are allowed to use suitable short forms in your answer, especially for representing physical quantities or their units.
Notes on the Limitations and Improvements of Question 2:
1. Two/three readings are not enough to make a valid conclusion
- Take more readings and plot a graph
2. The value of (a physical quantity) is small so the percentage uncertainty of (the quantity) is large
- (The way to make the value of the quantity larger)
3. The movement/oscillation of (something) is affected by wind movement
- Use a wind shield when carrying out the experiment
4. Difficult to determine the start and end of oscillation/movement of (something) because it moves too fast
- Use a video camera with slow motion feature and timer to record the experiment with scale, then view the video playback frame by frame.
5. Difficult to release (something) without applying a force
- Use a mechanical hand to release the (thing)
6. Difficult to shape the plasticine into the shape of (something)
- Use a mould to shape the plasticine
7. Heat loss through the sides and bottom of beaker/container
- Use polystyrene container or insulate the beaker/container using a lid or lagging.
8. The (measuring instrument) is not precise enough
- Use another (instrument) with greater sensitivity and precision. You must state the precision of the suggested instrument.
9. The length/diameter/thickness of (something) is not uniform
- Measure the length around/along the (thing) and calculate the mean
10. Difficult to measure (something) due to (specific reason based on experiment)
- (Suggest a better way to measure it)
11. Parallax error when measuring (something)
- (Suggest a better way to measure it, such as use mirror scale)
12. (Something) moves
- (Way to keep it in the original position)
13. Difficult to maintain (something) at (a particular position) / maintain ruler vertical
- Use a clamp
14. Friction at pulley
- Apply oil to lubricate the pulley
15. Difficult to determine when (something) reach the maximum height because it remains there for too short a time
Difficult to take the reading of newton-meter immediately when (something) starts to move
because it moves suddenly
Difficult to start or stop the stopwatch immediately when (something) passes through (somewhere)
- Use a video camera with slow motion feature and (the measuring device) to video the experiment with scale, then view the video playback frame by frame.
General Tips:
Physics practicals are not as challenging as chemistry practicals, so if you concentrate and follow the instructions carefully you're on your way to an A. Revise as many past year papers as possible and you will begin to recognise the repeating pattern in all papers and learn how to answer them. Good luck!
1. During the test, read the question and all information given carefully. Make sure that you understand the experiment given. Certain parts of the question require you to record the readings from the experiment in a table. You should draw the tables before carrying out the experiment so that you can record your readings in the table straight away during the experiment. Then, carry out the experiment by following the steps given in the question exactly. You need to apply your Physics practical skills when carrying out the experiment.
2. Do not panic if the context of the practical experiment appears unfamiliar. Where appropriate, the question paper will tell you exactly what to do and how to do it.
3. If you find yourself in real difficulty setting up your practical equipment you may askyour supervisor for help, although you may lose one or more marks for this.
4. When recording readings from an measuring instrument (except metre rule, vernier calipers and micrometre screw gauge), the number of decimal places used should be equal to half of the smallest division of scale of the instrument (For example, if the instrument's smallest division of scale is 0.1, you should record the reading to the nearest 0.05, which is 2 decimal places.) For digital instruments (except digital stopwatch), the number of decimal places used should be the same as that shown on the display. The reading should be recorded to the nearest 0.1cm for metre rule, 0.01cm for vernier calipers, 0.01mm for micrometer screw gauge and 0.1s for stopwatch (both analogue and digital). In all cases, do not give more or less number of decimal places. You must also write the correct units.
5. To save time, draw a single table for your results before taking any readings and enter your readings in the table as you take them (so that you do not waste time having to copy them later).
6. In most cases, you should take each reading twice, then calculate and record the mean of the 2 readings. Some questions are worth 2 marks, which means you get one mark for repeating. Ensure that you show in your answer both readings and the calculation of their mean. However, for the part in Question 1 which requires you to record readings in a table, questions that carry only 1 mark and questions which state that repeated readings are not required, you only need to take each reading once and record it straight away.
7. All the raw readings of a particular quantity should be recorded to the same number of decimal places which should in turn be consistent with the uncertainty in the readings. Each column heading in your table must contain both a quantity and its unit. For instance, if you have measured time “t” in seconds, your column heading would bewritten as “t/s”.
5. When plotting a graph, draw both the horizontal and vertical axis on the graph paper correctly. Label both axis correctly and state the unit (if any). Use a suitable scale for both axis and do not use any odd scales such as 3:10. Both the x-axis and y-axis need not start from 0. The scales should be chosen such that the points plotted on graph cover at least half of the graph paper. The markings on the scales should not be more than 3 large squares apart. Plot all points on the graph accurately. The points should be accurate to half a small square. For all the points, their diameter should not be larger than half a small square. Then, draw the correct straight line or curve. When drawing the straight line or curve, it should pass through all points on the graph if possible. If this is not possible, the line or curve should pass through as many points on the graph as possible, all the points should be close to it and the number of points above and below the line or curve should be almost equal.
6. When determining the gradient of the line of graph, choose 2 points on the line and draw a triangle. The distance between the 2 points chosen should be at least half the length of the line. When determining the y-intercept of the line of graph, if the x-axis starts from 0, you can read it off directly from the y-axis of graph, or if the x-axis does not start from 0, you should choose a point on the line, preferably one of the points that you used to calculate its gradient, and substitute its x and y values as well as the gradient into the equation y=mx+c to determine the value of c which is the y-intercept.
7. For any questions involving calculation, the number of significant figures of your answer should be equal to or one more than the number of significant figures of the raw value used in the calculation with the least number of significant figures. You should show all workings and do not skip any important steps. You must also write the correct unit for the final answer if it is not provided. You are not allowed to write extra solutions or answers. If you do so and any of the answers or solutions is wrong, marks will be deducted. For a calculation question which requires you to use your answer from the previous question, even if your answer for the previous question is wrong and you use it for this question causing your answer for this question to be wrong, usually you will still get full marks for this question as long as your calculation for this question is correct. This is known as 'error carried forward'.
8. For the part of Question 2 which asks you to estimate the percentage uncertainty in a particular value, in most cases the absolute uncertainty used to calculate the percentage uncertainty should be equal to twice the smallest division of scale of the instrument used to measure the value (For both analogue and digital stopwatch, the absolute uncertainty used should be 0.2s). This is because the measurement for this part is often difficult to be done accurately.
9. For the part of Question 2 which asks you whether your results support the suggested relationship between 2 variables, you have to calculate the percentage difference between 2 values of a constant which is obtained in previous part of the question. The suggested relationship is supported if the percentage difference is 5% or less and not supported if the percentage difference is more than 5%. The percentage difference is equivalent to the difference of the two values divided by the largest value.
10. For all questions, you should use the correct experimental and Physics terms in your answer. Do not replace them with other terms that are inappropriate, even if their meaning are the same. You should spell all experimental and Physics terms correctly. If you can't do so, try to spell it in such a way where it sounds the same as the actual term when read out. Marks are usually not deducted for spelling errors in experimental and Physics terms as long as it still sounds the same and that it is not easily confused with other terms. If you spell other terms wrongly or if you make grammatical errors in your answer, marks will not be deducted for as long as the examiner can understand what you are writing. You are allowed to use suitable short forms in your answer, especially for representing physical quantities or their units.
Notes on the Limitations and Improvements of Question 2:
1. Two/three readings are not enough to make a valid conclusion
- Take more readings and plot a graph
2. The value of (a physical quantity) is small so the percentage uncertainty of (the quantity) is large
- (The way to make the value of the quantity larger)
3. The movement/oscillation of (something) is affected by wind movement
- Use a wind shield when carrying out the experiment
4. Difficult to determine the start and end of oscillation/movement of (something) because it moves too fast
- Use a video camera with slow motion feature and timer to record the experiment with scale, then view the video playback frame by frame.
5. Difficult to release (something) without applying a force
- Use a mechanical hand to release the (thing)
6. Difficult to shape the plasticine into the shape of (something)
- Use a mould to shape the plasticine
7. Heat loss through the sides and bottom of beaker/container
- Use polystyrene container or insulate the beaker/container using a lid or lagging.
8. The (measuring instrument) is not precise enough
- Use another (instrument) with greater sensitivity and precision. You must state the precision of the suggested instrument.
9. The length/diameter/thickness of (something) is not uniform
- Measure the length around/along the (thing) and calculate the mean
10. Difficult to measure (something) due to (specific reason based on experiment)
- (Suggest a better way to measure it)
11. Parallax error when measuring (something)
- (Suggest a better way to measure it, such as use mirror scale)
12. (Something) moves
- (Way to keep it in the original position)
13. Difficult to maintain (something) at (a particular position) / maintain ruler vertical
- Use a clamp
14. Friction at pulley
- Apply oil to lubricate the pulley
15. Difficult to determine when (something) reach the maximum height because it remains there for too short a time
Difficult to take the reading of newton-meter immediately when (something) starts to move
because it moves suddenly
Difficult to start or stop the stopwatch immediately when (something) passes through (somewhere)
- Use a video camera with slow motion feature and (the measuring device) to video the experiment with scale, then view the video playback frame by frame.
General Tips:
Physics practicals are not as challenging as chemistry practicals, so if you concentrate and follow the instructions carefully you're on your way to an A. Revise as many past year papers as possible and you will begin to recognise the repeating pattern in all papers and learn how to answer them. Good luck!
really helpful!!!
