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Paper format:
There are two questions in each paper. Each question should take one hour as both questions are of 20 marks.
Question number 1:
Outline: it requires candidate to collect data, plot a graph and draw simple conclusions.
Question number 2:
Outline: No graph will be required. It will require candidates to follow an inaccurate method, take several readings and then evaluate the results. It requires candidates to identify the problems faced in experiment and suggest improvements that can be made.
Now, before starting on the tips to ace the Physics Practical Paper 3, you should keep this thing in mind that most of the marks are for working, presentation and conclusions. So even if your practical work is not very accurate you should move to the tables, graph and working without wasting time in making it more accurate. There are only 2 marks of quality on whole paper. Why lose rest of the marks due to 2 marks only? Don't get me wrong though. I don't mean that don't do the practical accurately but I mean to say that don't waste extra time in making it more accurate and leaving no time to complete rest of the paper.
I will discuss each point given in the Mark Scheme below.
Question 1:
In this question, first set up the apparatus in exactly the same manner as shown on the question paper. The first part of this question usually involves measuring something like diameter of a wire, length of some part of experiment apparatus, potential difference, current etc. While measuring you should ensure that you present the data to the appropriate number of significant figures so that if reflects the least count of the device being used for example:
* Below is the animation, showing: How to use Micrometer Screw Guage?
http://www.gceguide.com/wp-content/uploads/2016/07/Micrometer_no_zero_error.gif
** Below is the animation, showing: How to use Vernier Calipers?
http://www.gceguide.com/wp-content/uploads/2016/07/using-a-caliper.gif
In some cases, you have to measure something and judging by the space provided you have to show the evidence that you have taken repeated readings and averaged them out. Say you have to measure the diameter of a sample of wire, so using the micrometer screw gauze take 3 readings in three different parts along the length of the wire and show:
d = (d1+d2+d3)/3
and show the value calculated. Also remember to add appropriate units along with the individual readings you measure.
Then it says to repeat the procedure and get six different sets of data in a table. Students often have this thing out of their mind that the presentation is important and CIE in its examiner’s report terms such students as ‘weak candidates’. So first thing first, know how many variable you have to measure and/or calculate so you could draw appropriate columns.
Now before moving onto how to construct a 'nice' table, let's first consider what actually is demanded by the examiner in the table. A 'nice' table should have these features:
1) Range and distribution
Largest possible range is required. It means that for example if you have to measure length (L) from 0-100 cm, so we must take highest range while keeping the difference constant and getting 6 set of readings. The difference you can take here is 15, so the readings of L you'll take will be: 15 cm, 30 cm, 45 cm, 60 cm, 75 cm, 90 cm. These values of L you have cover almost the whole range of values possible from minimum to maximum. Same applies if you have set of resistors and you are asked to make different combinations of resistors to yield different values of resistances. These values of resistance must cover the whole range possible, like from minimum to maximum value possible (here keeping the difference between individual values of resistance for different combinations common is not necessary!)
2 ) Quality of data
In a nutshell this one mark is for how close your readings are to the readings of supervisor and does your readings have the points which make them look actual readings instead of made-up readings such as: (1) scatter of points about the graph, due to random error the points will never lie on a straight line (2) the trend is correct like dependent variable increasing with increasing independent variable and so on.
You will get accuracy marks if you actually write the values which are there on the equipment instead of making your own and if you did the experiment as accurately as supervisor.
3 ) Table
(i) Layout:
You will draw one single table with headings. Each heading will have the name or symbol of quantity with it's standard units in brackets of after slash such as “L /m” or “Temperature (K)”. using T can cause confusion so better write temperature or time instead of T or t unless the question explicitly says something like “ t=time period”. Writing “L m” or “temperature K” is not accepted.
(ii) Raw data
The data must be up to to the same precision. 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 precision of the measuring instrument.
There are two questions in each paper. Each question should take one hour as both questions are of 20 marks.
Question number 1:
Outline: it requires candidate to collect data, plot a graph and draw simple conclusions.
Question number 2:
Outline: No graph will be required. It will require candidates to follow an inaccurate method, take several readings and then evaluate the results. It requires candidates to identify the problems faced in experiment and suggest improvements that can be made.
Now, before starting on the tips to ace the Physics Practical Paper 3, you should keep this thing in mind that most of the marks are for working, presentation and conclusions. So even if your practical work is not very accurate you should move to the tables, graph and working without wasting time in making it more accurate. There are only 2 marks of quality on whole paper. Why lose rest of the marks due to 2 marks only? Don't get me wrong though. I don't mean that don't do the practical accurately but I mean to say that don't waste extra time in making it more accurate and leaving no time to complete rest of the paper.
I will discuss each point given in the Mark Scheme below.
Question 1:
In this question, first set up the apparatus in exactly the same manner as shown on the question paper. The first part of this question usually involves measuring something like diameter of a wire, length of some part of experiment apparatus, potential difference, current etc. While measuring you should ensure that you present the data to the appropriate number of significant figures so that if reflects the least count of the device being used for example:
- Micrometer Screw Gauge*: 0.01 mm
- Meter rule: 0.5 mm
- Vernier Caliper**: 0.1 mm
- Protractor: 0.5 degrees
- Graduated cylinder: 1/2 of the least count
- Time: 1 decimal place
* Below is the animation, showing: How to use Micrometer Screw Guage?
http://www.gceguide.com/wp-content/uploads/2016/07/Micrometer_no_zero_error.gif
** Below is the animation, showing: How to use Vernier Calipers?
http://www.gceguide.com/wp-content/uploads/2016/07/using-a-caliper.gif
In some cases, you have to measure something and judging by the space provided you have to show the evidence that you have taken repeated readings and averaged them out. Say you have to measure the diameter of a sample of wire, so using the micrometer screw gauze take 3 readings in three different parts along the length of the wire and show:
d = (d1+d2+d3)/3
and show the value calculated. Also remember to add appropriate units along with the individual readings you measure.
Then it says to repeat the procedure and get six different sets of data in a table. Students often have this thing out of their mind that the presentation is important and CIE in its examiner’s report terms such students as ‘weak candidates’. So first thing first, know how many variable you have to measure and/or calculate so you could draw appropriate columns.
Now before moving onto how to construct a 'nice' table, let's first consider what actually is demanded by the examiner in the table. A 'nice' table should have these features:
1) Range and distribution
Largest possible range is required. It means that for example if you have to measure length (L) from 0-100 cm, so we must take highest range while keeping the difference constant and getting 6 set of readings. The difference you can take here is 15, so the readings of L you'll take will be: 15 cm, 30 cm, 45 cm, 60 cm, 75 cm, 90 cm. These values of L you have cover almost the whole range of values possible from minimum to maximum. Same applies if you have set of resistors and you are asked to make different combinations of resistors to yield different values of resistances. These values of resistance must cover the whole range possible, like from minimum to maximum value possible (here keeping the difference between individual values of resistance for different combinations common is not necessary!)
2 ) Quality of data
In a nutshell this one mark is for how close your readings are to the readings of supervisor and does your readings have the points which make them look actual readings instead of made-up readings such as: (1) scatter of points about the graph, due to random error the points will never lie on a straight line (2) the trend is correct like dependent variable increasing with increasing independent variable and so on.
You will get accuracy marks if you actually write the values which are there on the equipment instead of making your own and if you did the experiment as accurately as supervisor.
3 ) Table
(i) Layout:
You will draw one single table with headings. Each heading will have the name or symbol of quantity with it's standard units in brackets of after slash such as “L /m” or “Temperature (K)”. using T can cause confusion so better write temperature or time instead of T or t unless the question explicitly says something like “ t=time period”. Writing “L m” or “temperature K” is not accepted.
(ii) Raw data
The data must be up to to the same precision. 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 precision of the measuring instrument.