MINISTRY OF EDUCATION
FIJI SEVENTH FORM CERTIFICATE
EXAMINATION
2012
PHYSICS
2.
MINISTRY OF EDUCATION
FIJI SEVENTH FORM CERTIFICATE EXAMINATION 2012
EXAMINER’S REPORT
PHYSICS
PAPER 1
The 2012 Fiji Seventh Form Physics Papers were prepared according to the prescription set out for this course by the Ministry of Education. Other factors taken into consideration were the
circumstances surrounding those candidates of the twenty- odd schools who were sitting this
examination for the first time. The availability of the recommended textbooks, laboratory equipment for their practical classes and perhaps the years of teaching experience of their mentors were also considered.
Overall, it was noted that candidates wrote more Physics in their scripts compared to past years where they submitted more of a blank paper than a filled one. Consistency marking was implemented where applicable, ½ marks were awarded for some formulae, for correct SI unit conversions and correct substitutions. Recalling of the correct formula was the biggest challenge for without these there was nothing more that could be done right.
The candidates together with their teachers are commended for their commitment and efforts throughout the year.
SECTION A: MULTIPLE-CHOICE QUESTIONS
1 A* B C D 16 A B C* D
2 A B* C D 17 A B* C D
3 A B C* D 18 A B C D*
4 A B* C D 19 A B* C D
5 A B C* D 20 A* B C D
6 A B* C D 21 A B C* D
7 A B* C D 22 A B* C D
8 A B C D* 23 A B C* D
9 A B* C D 24 A B C D*
10 A B C* D 25 A B C D*
11 A B* C D* 26 A* B C D
12 A B C D* 27 A B C D*
13 A B C D* 28 A* B C D
14 A* B C D 29 A B C* D
15 A B C* D 30 A B* C D
3.
CLOSE –UP ANALYSIS
SECTION A
Q.1. Options “C” and “D” seemed to be the common response of candidates. Approximately 10% of the sample chose the correct answer – A. Knowledge of the rules of combining
measurements was tested.
Q.2. “D” was the common response. Approximately 35% of the sample had the correct answer. Common knowledge of the basic facts of projectile was tested.
Q.3. Basic Physics concept was tested and only 40% of the sample got it right.
Q.4. The least opted answer was “A” and there was an equal distribution of the other three. The candidates’ comprehension skills and application of momentum (linear) conservation were tested.
Q.5. “B” and “D” played their role as distracters fairly well and only 40% of the sample got the correct answer. Concept tested – conservation of angular momentum.
Q.6. 40% of the sample got the right answer. Knowledge of the basic inertia formula was tested and correct substitution of values from the diagram.
Q.7. Poorly done, where only 7% of the sample got the correct answer. This is application question on Gravitation.
Q.8. Well answered. 60% of the sample got the correct answer. This item tested basic recall of the characteristics of SHM.
Q.9. Resolution of the weight of a mass on an inclined plane was applied here with coefficient of friction taken into consideration. 47% of the sample had the correct option.
Q.10. Well done. 67% got this question correct. Concept of energy transformation well understood.
Q.11. Common answer was “C”. However, 67% of the sample got this question correct. This question required knowledge of the relationships between resistivity, conductivity and temperature of conductors and semi-conductors.
Q.12. Candidates did not do well in this question. Only 33% of the sample got it correct. Common answer was 2A which is option “C”. One had to visualise a full cycle motion of a spring to get this right.
Q.13. Well answered. 77% of the sample got this correct. It shows a good recall of the correct formula for Doppler Effect.
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Q.15. Only 33% of the sample got this question correct. Questions 14 and 15 tested their understanding of εmf and internal resistance of a cell.
Q.16. Generally well done. 73% of the sample got it right. Common incorrect answer were “A” and “D”, arrived at without the proper conversion of 3.2 µC.
Q.17. 50% of the sample got this question correct and exactly the same percentage got it wrong. This was a very straightforward question, however, and the analysis shows that some candidates fail to associate that electromagnetic waves travel at the speed of light.
Q.18. Not well done, there were varied answers which show that the concept is not well understood.
Q.19. Not well done. Only 43% of the sample got this correct. Derivation of units is an easy concept when taught well.
Q.20. Most common answer was “D”. 57% of the sample got this question correct. The candidates would have to recall the correct formula and then use the concept of relationships to arrive at the correct answer.
Q.21. 57% of the sample got this question correct. A basic understanding and knowledge question on interference of light.
Q.22. An application – type question where a candidate is required to recall the correct formula and then use the concept of relationships to arrive at the correct answer. 43% of the sample got this question correct.
Q.23. A poorly answered question where 0% of the sample got this question correct. Common answer was “A” (87%). The application of time constant was required here.
Q.24. 40% of the sample got this question correct and 40% also chose “C” as their answer. This question is similar to Questions 20 and 22 but in three different topics.
Q.25. 60% of the sample got this question correct thus satisfactorily answered. Together with Question 26, there is a sketchy understanding of Thin Film Interference.
Q.26. 23% of the sample got this question correct. Poorly answered.
Q.27. Satisfactorily answered. 50% of the sample got this question correct. Diagram interpretation needs emphasis.
Q.28. Satisfactorily answered. 57% of the sample got this question correct. Recalling the simple speed formula and applying it to the dimensions given in the diagram was required.
Q.29. 70% of the sample got this question correct. Well done. Similar question type as Question 28.
5.
SECTION B
QUESTION 1
Majority of the candidates did very well in this question. For those that did not arrive at the correct answer, they earned marks on the use of the correct formulae. Almost 5% of the candidates were not able to provide the conversion of the radius (cm) into SI Unit of metres (m).
QUESTION 2
(a) Most of the candidates reached νi = 8.56 m/s instead of ν = 12.10 m/s. These candidates
earned themselves 1 ½ marks out of the full 2 marks. Interestingly, the conversion of the 12 ft to metres was very well attempted.
(b) Most candidates had a different interpretation of the “leap”. They took it as the range instead of the horizontal distance corresponding to the leap of the height the puma can jump.
QUESTION 3
(a) Satisfactorily done. Of the sample analysed, about 37% scored ½ mark. Most candidates lost marks through failure to convert 10 cm to 0.1 m and also by using the wrong formula.
(b) Poorly done. Of the sample analysed, about 34% did not attempt this question at all while 47% attempted but scored 0. Most could not work out the momentum simply by equating the centripetal force to magnetic force which are the two main forces acting upon the proton orbiting inside the solenoid.
QUESTION 4
(a) Well done. About 53% score full marks while 39.5% either scored 0 or left the space blank. Calculation of total capacitance in series and parallel connection needs to be taught
thoroughly in class.
(b) Well done by those that attempted this question. Consistency marking was applied in this question. The formula Q = VC was well understood by candidates and was quiet evident in their response to this question.
(c) Poorly done. Most candidates failed to see that the voltage across the 3 µF capacitor is the same as the voltage across the 6 µF, the equivalent capacitance for the 3 µF parallel combination. Consistency marking was also applied to this question.
QUESTION 5
Average mark of 1.73 out of 3. Generally, poorly done.
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(b) Well done. Candidates were able to recall the formula V = Ed. Common mistakes were in the conversion of units form cm to m.
QUESTION 6
Average mark of 1.27 out of 3. Generally, poorly done.
(a) Well done. Common mistakes were the recalling of an incorrect formula and failure to convert the cm to m.
(b) Very poorly done. Answer spaces were left blank which was an evidence of lack of understanding.
QUESTION 7
(a) With the inclusion of fractions in the wave equation contributed to the candidates’ poor performance. Only 30% of the sample got full 1 mark.
(b) 33% of the sample got full 1 mark. Candidates could not recall the correct formula to start with which is
(c) 50% of the sample got full 1 mark. Consistency marking was used and candidates were quite familiar with the basic wave equation of .
QUESTION 8
(a) Poorly done. Only 13.33% of the sample got the full 1 mark. About 70% got partial marks. This is a common examination question and the candidates’ response showed lack of emphasis of the conversions of galvanometer in class.
(b) Only 26.67% of the sample got full 1 mark. Concept was poorly understood.
QUESTION 9
Overall, this question was generally not well done. About 73% of the sample scored 1 ½ marks or less.
(a) Not well done which showed that candidates were not applying theoretical concepts learnt to everyday situations or lack of emphasise on the teacher’s part..
(b) Not well done. Candidates were able to get partial mark by recognising an inversely proportional relationship. Teachers need to spend more time on the concept of relationship.
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QUESTION 10
Not well done. 70% of the sample scored 1 mark or less. About 50% got no mark at all. Since the value of Planck’s constant was not given in the “constant sheet”, some candidates tried using the formula but substituted the energy values given for L and n.
SECTION C
QUESTION 1
(a) Force system
This question was poorly answered due to the inability of most candidates in comprehending the appropriate method and technique of analysing any type of force system. It was also observed from the nature of their answers that they were unable to apply the same calculations that were used in a two-way force system to a three-way system or from linear force system to a combination of linear and an inclined plane. As such they ended up with the wrong values for acceleration, T1 and T2. This was a direct result of a lack of linking to forms 5 and 6
understanding on this concept, insufficient revision and concept not well taught.
(b) Wheatstone Bridge
Even though it was a fair question, majority of the candidates were unable to answer it correctly. Most of those that attempted gave partial answers to both parts of the question. A good number of candidates used the correct formula and substitution but were unable to do the math required in part (i) and wrong calculation of the total resistance (in a series and parallel combination) before finding the current in part (ii). This is a very simple concept to
comprehend but not well covered or not taught at all as was evident in marking this question.
(c) Vibrating Air columns Open at Both Ends
Most of the candidates that attempted this question used the wrong value of the wavelength. As a result of their inability to link the type of resonance to the correct type of pipe which determines the wavelength, it affected the next resonant frequencies.
(d) LCR Circuit – Radio Receiver
The resonance frequency circuit was not well understood by most candidates and as a result they used numerous forms of the resonant frequency formula. For those that were able to use the correct formula still had problem transposing the formula in order to make “C” the subject thus finding its precise value. A good number of candidates were confused with the correct substitution of the rms current whereby they ended up with a double division.
8.
QUESTION 2
76.67% of the sample attempted this question. The highest score was 9 out of 10 whilst the lowest score was ½.
(a) Poorly answered. It was evident from the candidates’ response that the concept of two-dimensional collision was not taught in Form 7 and the candidates used their knowledge of linear momentum learnt in Forms 5 and 6 to get some marks. Teachers are reminded to teach the Form 7 prescription and not to assume that candidates can relate previous years’ work.
(b) (i) Most candidates could not determine the value of the wavelength from the graph hence could not calculate the speed of the wave.
(ii) Very poorly done.
(iii) Poorly done. Most candidates had no idea what they were doing.
(c) (i) Satisfactorily done because candidates either failed to convert 4 mm2 and 12 mm into their appropriate units or converted them wrongly. Teachers are reminded that SI unit conversions are necessary and enough time should be devoted to teaching this as they can gain marks by doing these right.
(ii) About 86% of the candidates stated the correct formula but failed to get the correct value of current because they failed to convert the drift velocity of 0.5 mm/s to m/s. A note to the teachers: Emphasis placed on “n”. It is the number of electrons per cubic metre of the wire.
(iii) Another well known formula, J = I/A was used by about 86% of the sample.
Candidates got partial mark because they failed to convert the area of 4 mm2 correctly. Consistency marking applied from (ii) to (iii).
QUESTION 3
Not a very popular choice for many candidates. Only 32% of the sample attempted this question. However, only very few candidates scored full marks.
(a) (i) Well done.
(ii) & (iii)Response clearly indicated a poor understanding of the concept tested in this question.
(b) (i) Well done by those who attempted this question. For those who scored ½ mark, it was only for recalling the formula correctly.
9.
(ii) Very well done.
(iii) Well done by those who attempted this question and they were able to recall the formula
QUESTION 4
Almost 90% of the candidates opted for this question from the sample considered.
(a) (i) Most of the candidates gained marks for the correct answer but some failed to provide the correct units.
(ii) Almost 50% of the candidates calculated the correct answer. Approximately, 40% of the candidates were not able to provide the correct formula.
(iii) Most of the candidates earned full marks in this question but there were some who used the concept of conservation of energy involving rotational kinetic energy to get their answer but were rewarded for the correct linear kinetic energy formula.
(iv) Poorly answered question. Candidates failed to understand the inverse relationship that would reason out for the answer. Majority just mentioned that the motion of the bike would become faster.
(b) A challenging question for the candidates since they were not able to use the appropriate magnetic field formula. Most of the candidates used other magnetic field formulae and had difficulty in getting the correct radius. 95% of the sample failed to make any attempt in determining the magnetic field strength outside the toroid.
(c) (i) 60% of the candidates got full marks in this question. But those who failed had problems in not understanding that the Electric field (E) is a vector quantity thus direction needs to be considered in the calculation of the resultant E. Most candidates simply added the two E values. Some used the electric potential formula to determine E. A handful used the wrong value of k (the constant), i.e. 2 x 10-7 instead of 9 x 109. (ii) Some used the E formula for part (i) in this part. A handful used the Pythagoras’
theorem to find the resultant electric potential. Again, some chose the wrong value of k in their calculations.
QUESTION 5
Only 3% of the sample chose to answer this option.
(a) The concepts related to the vertical circle were poorly understood by the candidates.
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(c) (i) Most candidates recalled the correct formula but failed in determining the correct value of “d” in when the lines per cm is given.
(ii) Most got partial marks for getting n = 4. Determining the total number of maximas need emphasis.
QUESTION 6
(a) (i) A simple concept to remember, however, most candidates failed to do so.
(ii) Not done as expected. Most candidates mixed up the formula and got incorrect answer.
(b) (i) Poorly done. Those that got 0 failed to recall the correct formula.
(ii) Not done to expectation. These diagrams were introduced in Form 6.
(c) (i) Only 10% of the sample managed to get full marks. The key concept here was been able to identify the two forces acting on the body and equating them.
i.e.
(ii) A simple substitution question, but candidates failed to convert the 6400 km to m.
(iii) Well answered by those that understood the concepts of escape speed and gravitation.
(d) Poorly done. Emphasis must be placed on the electromagnetic spectrum, the components and the trends of frequency, energy and wavelengths.
QUESTION 7
This was a popular option. Highest score was 10 and the lowest score was 0
(a) (i) Generally well done. Most candidates were able to get the correct equation.
(ii) Generally well done. Most candidates got partial marks or full marks. Common error was not equating the algebraic sum of the voltage drops to zero. Teachers must emphasise that not equating the voltage drops to zero is a minus ½ mark.
(iii) Not well done. The mathematics behind solving equations simultaneously is beyond the capability of most candidates.
(b) (i) Generally well done. Candidates were able to recognise the phase angle as or 45˚.
(ii) Not well done. Most candidates left blank spaces. The mathematics involved here must be emphasised.
11.
PAPER 2
The general impression as evident from the candidates’ responses was that practicals are not being considered as an integral part of the understanding of the Physics concepts. A lot of emphasis is being placed in formula recalling and problem solving.
QUESTION 1
(a) (i) & (ii) Both poorly done. Only a few candidates were able to score full marks in these questions. In part (i), most candidates failed to multiply 0.02 by the 3 intervals from A to D.
(b) (i) & (ii) Poorly done as well. It was quite evident from the candidates’ response that experiments were not conducted. 63.8% of the sample got zero.
QUESTION 2
(a) (i) Majority of the candidates were able to get full marks but approximately 15% just gave acceleration as their answer which did not earn any marks at all.
(ii) 80% of the candidates gave answers in terms of a directly proportional relationship form i.e. as the y-axis increase, the x-axis also increases which does not answer the question.
(iii) Approximately 35% of the candidates were only able to get full marks whereas the majority earned partial marks in showing some calculation of a slope. Identifying the correct unit was a problem.
(b) (i) Almost 58% of the candidates got full marks whereas 36% gave their answers as kinetic energy and potential energy for which they got only ½ mark.
(ii) 40% of the sample got full marks. Most candidates were unable to answer the question specifically either they were selective or they did not understand the question.
Interestingly, about 15% of the sample gave their answer as which was the assumption made for this experiment.
QUESTION 3
(a) (i) Well done. Common mistake was in the use of the wrong formula.
(ii) Well done. Common mistake was again in recalling the correct formula.
(iii) Well done.
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QUESTION 4
(a) (i) Poorly done. Only about 7% of the sample got full marks. Candidates failed to draw two loops, the two-way switch and most could not differentiate between a cell and a DC supply.
(ii) Recalling the correct formula was not a problem to many. Only about 27% of the sample got full marks. Those that got partial marks failed to convert the 2 µF and 4 MΩ.
(b) (i) Poorly done. Only 20% of the sample got full marks. Emphasis on this is needed.
(ii) Well done.
QUESTION 5
(a) Generally, not well done. Candidates were not able to match the correct electrical symbol to its name. This is a basic requirement in practical work, to be able to name the equipment or materials used with their preferred symbols. Symbol I (battery) was incorrectly matched to E (cell).
(b) (i) Not well done. There is a lack of understanding in the correct usage of electrical metres. It seemed that candidates did not know what the question was which also implied that they probably had not seen a multi-scale meter as such.
(ii) Poorly done. Candidates did not know how to correctly read off an instrument as such. Emphasis needed.
(iii) Satisfactorily done. No mapping of concepts taught in theory to the practical.
QUESTION 6
Doppler Effect:
(i) It was found that there were numerous variations to the shape of the circular wave, with some drawing concentric circles while others drew the opposite. This is a clear indication of lack of understanding of the concept in the three different situations.
(ii) Well answered as the answer was part of the question.
(iii) Wrong formula was the cause of incorrect answer.
QUESTION 7
(a) Only 23% of the sample got full mark. Emphasis must be made on the importance of taking several readings and using the average value in any calculation.
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(c) Poorly done. It was evident from the candidates’ response that this experiment was not done.
QUESTION 8
(i) Well done.
(ii) Not well done.. Emphasis is needed on interpreting graphs.
(iii) No one in the sample got full mark. Emphasis is needed on graph interpretation.
(iv) About 23% of the sample got full mark. Emphasis is needed on graph interpretation.
