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T A S M A N I A N Physics

C E R T I F I C A T E Subject Code: PHY315109 O F E D U C A T I O N 2012 Assessment Report

2012 Assessment Report

The answers to the 2012 paper are at the end of this report. This year they are presented in hand written form by the respective markers on the actual paper so that future candidates can better appreciate the detail the marking examiners were looking for in the solutions. They are not necessarily the only responses that were given credit by the marking examiners. About 15% of candidates didn’t complete Part 4, leaving the majority of questions 20 and 21 blank and sacrificing 14 marks. This was the case in the other three parts as well, but to a lesser extent. The format for the ‘show that’ questions continues to work very well. The only issue is some candidates did not show their final value to 3 significant figures as requested and were thus penalised. As usual, the quality of communication varied widely but there were no illegible scripts and the use of significant figures and appropriate units seemed better. Not giving a direction for vectors was still far too prevalent. Too many candidates did not show complete working and thus could only be given 0 when the answer was wrong. In order to give credit when an answer is wrong markers need to be able to follow the working. As usual, many candidates completed the appropriate calculation to answer a question but then failed to complete their answer by making an appropriate statement relating their calculated result back to what the question was asking. PART 1 – Criterion 5 Question 1 This question was very poorly answered possibly because it was a little different. As can be seen from the solutions it is reasonably straightforward when the correct approach is adopted. Question 2 a) OK, but a common mistake was stating ‘Fnet = 0 as there was constant speed’. b) A large proportion confused weight with mass but otherwise well done. c) The diagram was often poor and not supported by a clear explanation based on an

appropriate equation.

Physics 2

Subject Code: PHY315109

2012 Assessment Report

Questions 3 and 4 Well done by the majority of candidates. Note: A jet does not operate by the exhaust material striking something to give the thrust! Question 5 Generally well done. In Part (d) the diagram was often not used as requested! Part (e) was a real discriminator, with few candidates completing the section successfully even though they started with the appropriate proportionality. Question 6 A relatively easy question that was done poorly or not attempted by far too many candidates, suggesting more practice is needed on this type of question. PART 2 – Criterion 6 Question 7 The vector nature of the field was ignored by far too many and not taking directions into account when answering questions involving vectors was disappointing. Part (c), which should be a gift of easy marks at this level, was poorly answered. This suggests more attention to drawing these types of diagrams is needed. Question 8 Obtaining the mass and charge of an alpha particle from the Information Sheet was a stumbling block for a significant number of candidates. There were a lot of calculator errors in this section and candidates are encouraged to look at their answers to check that they are reasonable. Question 9 a & b The circular and vector nature of the fields were not appreciated by many candidates

resulting in these parts being badly done. c) Converting to the correct units were an issue with this part. d) Well done.

Physics 3

Subject Code: PHY315109

2012 Assessment Report

Question 10 a) Poorly done. The angle of dip was not well understood. Many candidates did not know

that field lines come out of the ground in the Southern Hemisphere. b) Well done. c) Rarely correct with totally erroneous explanations abounding. Question 11 a & b Well answered by the majority. c &d Not well done at all by candidates. Field lines were labelled going the wrong way and

very few helixes were shown as the subsequent path of the particle. PART 3 – Criterion 7 Question 12 a) Good but too many candidates had an incorrect phase change. b) Poorly done with the most common error being candidates not referring to Newton's

Laws as requested in the question. c) Well done. d) Poorly done; candidates did not follow the instruction to refer back to the previous

three parts. Question 13 A well-answered question apart from part (b)(ii), where the maths got the better of a number of candidates. Question 14 Well answered. Question 15 a) This was poorly done. There was lots of confusion about the meaning of the symbols in

the formula, suggesting not enough practice. b) Well done. c) Poorly answered. Most commonly candidates calculated how many wavelengths of red

light there were in 4.5mm, showing confusion between path difference and W.

Physics 4

Subject Code: PHY315109

2012 Assessment Report

Question 16 This question brought out a real weakness in the candidates' understanding of standing waves, beats and harmonics. Very few gave sufficiently detailed explanations. PART 4 – Criterion 8 Question 17 Generally well done. In these graphical questions it is expected that candidates use the values calculated earlier when answering the subsequent parts. In this case the value of h calculated in part (a) should have been used in latter calculations rather than the value given on the Information Sheet. Also the use of a ruler would have helped some candidates. Question 18 a) Many wanted to discuss penetration, without really understanding the penetrating

ability of X-rays. too often statements without consequences, or statements without reasons, were made eg. ‘X-rays are safer’ or ‘X-rays can be controlled’.

b) Very few addressed the word minimum, which was in bold in the question, but the rest was well done.

c) Well done, but for some reason many only gave their answer to one significant figure. d) Very few candidates recognised this as a conservation of energy question! This needs

addressing in future teaching. e) Well done. Question 19 a) Well done. b) Arrows everywhere was a common answer. Most went up rather than down! c) Candidates showed they could calculate a frequency but because of mistakes in Part b

they didn’t calculate the correct three. d) Many candidates were not sufficiently specific in their answers. The difference between

ground state and energy levels was important, not the energy level in isolation. This point was not clear in many answers.

Question 20 This question was quite well done. A very common error was the omission of units on the decay constant. This led to issues in Part e where non-compatible values, in terms of time units, for activity and the decay constant were used.

Physics 5

Subject Code: PHY315109

2012 Assessment Report

Question 21 This question was left blank by a lot of candidates but those that attempted it did a good job.

TASMANIAN QUALIFICATIONS AUTHORITY

PHY315109 Physics

ASSESSMENT PANEL REPORT

Award Distribution

Student Distribution (SA or better)

EA HA CA SA Total

This year 23o/o (56) 22o/o (54) 15Vo (37) 4OYo (1OO) 247

Last year 2Oo/o (62) 23o/o (70) 25Yo (78) 31% (e6) 306

Last year (allexaminedsubjects)

11 o/o 19% 39 o/o 30 o/o

Previous 5 years 21 o/o 23 o/o 29 o/o 27 o/o

Previous 5 years(all examinedsubjects)

11 o/o 19 o/o 4Q o/o 30 o/o

Male Female Year 11 Year L2

This year 79o/o (196) 21o/o (51) 0%o (1) 1O0o/o (246)

Last year 81o/o (248) 1e% (58) 0o/o (1) 100% (305)

Previous 5 years 77o/o 23o/o 0% lOOo/o