MINISTRY OF EDUCATION
FIJI SEVENTH FORM EXAMINATION
2010
PHYSICS
2.
MINISTRY OF EDUCATION
FIJI SEVENTH FORM EXAMINATION 2010
PHYSICS
EXAMINER’S REPORT
GENERAL
A total of 1405 candidates registered for the examination.
Students were examined on the following topics: Mechanics, Gravitation, Direct Current, Electrostatics, Simple harmonic motion, Travelling waves, Magnetism, Electromagnetism and Atomic Physics. Questions tested Knowledge, Comprehension, Analysis and Application of Form 7 Physics. The examination is wide in its coverage and student friendly in its general impression however representative of a Form 7 Physics standard.
The following comments are general on the various sections of the examination.
A good number of students scored very well. Such scores demonstrated a good command of the subject matter by students. Poor performance of students is attributed to lack of understanding of the subject content compounded with inability to do application and analysis type problems.
The following weaknesses were noted.
(i) Many students had difficulty doing conversions to SI units.
(ii) Many students recalled formula correctly but did poorly in the application.
(iii) Questions which require the use of vectors were done poorly. Teachers should emphasize the importance of vectors in problem solving.
(iv) Experimental procedures and application of concepts need to be understood well especially for Paper II.
(v) Full use of calculators is essential. Many students need help from teachers.
3.
PAPER 1
SECTION A
There are 30 multiple choice questions.
The responses in percentage for the random sample are tabulated below. The correct response for each number is marked with an asterisk (*).
Question A B C D Question A B C D
1 45 3 49* 3 16 3 41* 33 23
2 23 30 21 26* 17 4 8 70* 18
3 7 10 66* 17 18 56* 10 18 16
4 72* 10 5 13 19 13 43 33* 11
5 5 88* 2 5 20 28 21* 28 23
6 31 34* 20 15 21 9 11 26 54*
7 8 4 83* 5 22 59 11* 13 17
8 74* 11 5 10 23 33 18 6 43*
9 11 10 31 48* 24 20 13 57* 10
10 33 46* 16 5 25 8 15 57* 20
11 25 34 3 38* 26 21 70* 5 4
12 13 30 31 26* 27 33 8 48* 11
13 46* 7 34 13 28 1 82* 10 7
14 48* 13 11 28 29 57* 21 13 9
15 3 8 64* 25 30 6 7 20 67*
For Questions 1, 2, 6, 10, 11, 12, 16, 19, 20, 22, 23, 27 the distractors were effective. Only students who had a good command of the Form 7 physics scored. On the remaining 18 multiple choice questions, most candidates were able to comprehend the questions and perform calculations. Most candidates found the 18 questions quite easy.
4.
SECTION B
The TEN questions in this section were worth 3 marks each.
Q1. Candidates did well. Students who did not score in this question failed to ecognize that Tension (T) carries the weight of the system.
Q2. Generally well done. Many candidates failed to convert “h” to SI unit and did not perform the correct substitution.
Q3. Part (a) was well done. Many candidates did not analyse the forces as
Mg – Ff – Fx = (10 + 6) a in order to calculate the system acceleration and Mg – T = ma to
calculate the Tension.
Q4. Many candidates correctly recalled formulae U= -GMmR-1 and Ek = GMm/ 2R. The difficulty here was the determination of R.
Q5. Very well done by most candidates.
Q6. Generally well done. Candidates had difficulty converting km/hr to SI unit.
Q7. Most candidates failed to recall V = kq / R as potential and add the potentials.
Q8. Candidates generally did well. P = VI and E =Pt. The difficulty was the conversion of time to SI unit.
Q9. Generally well done. Most candidates knew that Ф = BA and V = N BA / t. Quite a number of students could not recall correctly the formula for induced voltage. Students were familiar with the application of Ohm’s Law, V= IR.
Q10. This was a challenge and most candidates could not score full marks. Knowledge of the right formula to use for this application question was a problem. Energy in eV and J was an issue for most candidates.
GENERAL COMMENTS ON SECTION C
C1. (a) Most candidates did not write the expression FR = mg + ma. Parts ii) & iii) were generally well done.
(b) Formulas C =EoA /d , Q = VC and V = Ed were well applied. Conversion of area to SI units did not happen in many of the answers.
(c) Most scored well. Some candidates could not equate ω =2πf to determine frequency before the use of V =fλ.
C2. (a) Generally well answered.
5.
(c) Conversion of area to SI unit was a challenge. The word rate appeared to be a problem to candidates.
(d) The calculation of sphere Area and the prefix nC were challenges. Otherwise it was fairly well done.
C3. (a) Formulas Q = It , J = I /A , J = nev and I = nevA were well quoted. The difficulties lie with the following calculations: Time in SI unit, Area in SI unit and the number of electrons ( 4.55 x 10 22 ) in the volume given.
(b) Very well answered. Teachers have taught Kirchoffs applications well.
C4. (a) The equation of Fc = Fg was well understood. Candidates were able to rearrange the relationship and determine R at 1.595 x 109 m. The subtraction of earth radius (r ) from R was a common problem. Use of V = 2 π R / T was well understood.
(b) Use of E = kQ /R2 was good. It was well done by many students. However ,many students failed to treat E as a vector quantity. Some students simply recalled Coulomb’s Law (F = kQQR-2
).
(c) Generally well done.
(d) Very well done.
C5. (a) Not many students had this correct. Formula L = mvR and conversion from radians to m/s was a challenge to students who attempted this question.
(b) Parts i) & ii) were well done. Many candidates did not realise that thickness of film required was λ /4 .
(c) Generally well done. Many students however could not recall equation hf = Ek + B and then equate hfo to B to determine the threshold frequency [B = ].
C6. (a) Very well done . Most recalled nλ = dsin θ. Students who lost marks did not use d = 1/N .
(b) Many candidates did well. Few possible approaches were shown by students. W =mad =Fd=Eqd =Vq. Many candidates recalled correctly the use of Eq =ma.
6.
C7. (a) Generally well done. The challenge to this projectile was the calculation of velocity (v) as a vector quantity for part iii).
(b) Xc and XL and Z has been well taught to students. The difficulty lies with the phasor
diagram.
PAPER II
The performance in this paper continues to reveal that in many schools of the Form 7 experiments is a non-performance. Concepts stressed during experiments seemed to have been taught in
isolation hence applications different from actual experiments appeared to have no relevance. As a result many candidates appeared “lost” in their answers to what was simple and basic in a F7 physics laboratory.
Q1. Correct readings to parts a) & b) were a problem. Part c) was well done by most candidates.
Q2. (a) Very well done.
(b) Difficulty is with parts ii) and iii). EkR = ½IW2
Q3. (a) Very well done by most candidates.
(b) Conservation of momentum well stated. The use of vectors in problem solving was lacking in many calculations.
Q4. (a) Generally well done.
(b) Applications of E =V/d , F = Eq ,and W =Eqd OR W =Vq were well done.
Q5. (a) Generally well done.
(b) Generally well done.
7.
(b) This part was generally well done.
Q7. (a) Generally well done.
(b) Recall of formula T = 2π ( m/k )½ . Some candidates failed to convert gram to SI unit.
Q8. (a) Generally well done.
(b) Very well done.
