Statistics
Year Number of candidates
Level of achievement
VHA HA SA LA VLA
2017 20 3 6 4 5 2
2016 17 2 4 6 5 0
2015 22 3 3 7 6 3
2014 14 0 5 4 4 1
2013 27 3 7 7 7 3
General comments
The 2017 Physics Senior External Examination was based on the Physics Senior External Syllabus 2000 (amended 2003).
Paper One Part A assessed Knowledge of subject matter and Part B assessed Scientific processes. Part A consisted of 15 multiple-choice questions and 10 short-response questions covering all syllabus topics. Marks allocated were in proportion to syllabus topic weightings.
Part B contained seven Scientific processes questions assessed against criteria specific to each question. Candidates were required to respond to all seven questions.
Paper Two assessed Complex reasoning processes and contained six questions assessed against specific criteria. Candidates were required to respond to all six questions.
Paper One
Part A: Knowledge of subject matter
Section 1 — Multiple-choice questions
Question 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Correct response B B C D C B B C C C B B A B C
Physics
2017 Senior External Examination: Assessment report
Section 2 — Short-response questions
This part of the examination required candidates to demonstrate their knowledge and ability by simple application of the syllabus topics. Many responses indicated that candidates had
knowledge of basic concepts and their typical use, but were not as practised in the application of these concepts as they could be. This was particularly evident when interpreting data in scientific diagrams.
Question 1
Most candidates clearly understood the notion of significant figures and could apply it in the situation given. The practice of choosing the lowest number of figures in such situations seems well established.
Question 2
Candidates generally converted percentage errors into absolute errors with few problems.
Question 3
Candidates were generally able to equate change in momentum with the product of force and time, as long as the units of time were managed. This meant the question was generally well done.
Question 4
This was a reasonably straightforward application of theory and most candidates did not have difficulty showing a solid understanding of this simple problem. It was interesting, however, that some candidates calculated the exact length of the displacement, accounting for vertical
movement, and then used this against the frictional force. The intent of the question was to look at the horizontal distance travelled and then add on the gain in GPE.
Question 5
The diagram did not seem to confuse candidates and they either answered it by stating the number of wavelengths along each line or by describing the path difference. Both of these approaches addressed the question. Some candidates forgot to mention the type of interference.
Question 6
In this problem, most candidates were able to use the appropriate formula, although some did not pay attention to the units used.
Question 7
The simple application of formula was generally done well. While the exact equation used is not represented in the resource booklet, it is a simple equating of two other equations. The additional requirement to calculate power was handled well enough by most candidates.
Question 8
Candidates were generally successful with this problem, having no difficulty locating the relevant information. Using the term ‘internal resistance’ did not seem problematic.
Question 9
Candidates who recognised the problem type had most success in using the formula correctly.
Question 10
Candidates did well in this question, generally representing the equation accurately and also identifying the type of decay.
Part B: Scientific processes
Question 1
Candidates were able to detect that there was a linear relationship for a particular range of masses but that this did not extend to the larger masses.
Question 2
Most candidates realised that an exponential decay graph was required. A small number made a linear graph.
Question 3
As usual for this type of problem, the success of candidates solving it varied. It may be useful to teach candidates to focus on key interaction points of the graph from which they could interpolate the others.
Question 4
Candidates typically plotted the points on the graph well, with a mostly sensible choice of axes.
The challenge of integrating the graphs and synthesising an answer to the question was met with varying levels of success. The range of acceptable answers was quite small. Candidate
responses were either in the range or far outside, perhaps indicating some guess work.
Question 5
The experimental design required for this question was generally not done well. While the situation and problem were simply phrased, the identification and control of variables was not generally effective. Very few answers controlled all variables and made sensible suggestions for data collection or experimental methods.
Question 6
This was quite a complex graph, although candidates generally understood what it was
displaying. When explaining the connection between the graphs, some candidates made a clear and correct interpretation and synthesis, but others clearly did not grasp what the question was asking, or could not determine the relationships between the graphs. More work in complex graphical representation, particularly in synthesising data from several data sources, could help with this shortfall.
Paper Two
Complex reasoning processes
Question 1
While the answer to this was simple to express, it required interpreting the circuit flow in a reasonably sophisticated manner. Candidate responses were varied, but many were successful.
Question 2
Candidates who were successful generally showed an ability to create the appropriate diagram first. From this point, most candidates understood how to proceed.
Question 3
There was some confusion about the ‘initial position’ and what value this should be, i.e. at 340 N.
However, candidates generally recognised this as a problem in potential energy with the initial information used to determine the spring constant.
Question 4
This was a complex but not difficult problem. Most candidates understood what was required, but had varying levels of success in working through to an answer.
Question 5
Candidates did quite well on this difficult problem. While some did not realise that a unit length should be used for calculations, others could get to a formulation of the problem that allowed them to find a solution.
Question 6
This was a straightforward problem, but judging by the responses, candidates were able to do the calculations for the refraction but had problems with the geometry of the situation. More work in geometrical analysis of such situations might be helpful.
Marker responses
The sample solutions on the following pages show possible ways of successfully responding to the questions. Other approaches and problem-solving strategies may be equally valid.
