Engineering Studies 2025 HSC exam pack

Students should:

• read the question carefully to ensure that they do not miss important components of the question
• avoid simply re-stating the question in their response
• have a clear understanding of key terminology in the question and recognise the intent of the question and its requirements
• engage with any stimulus material provided and refer to it in the response
• communicate ideas and information using relevant examples
• expect to perform some mathematical functions, interpret data/graphs/tables and assess information for accuracy, reliability and/or validity
• consider using graphical solutions if applicable
• review their response to ensure that it addresses the question requirements
• include all working in calculation responses, and set these out in a logical manner
• be familiar with relevant engineering terminology and use it correctly to enhance their answers
• use correct materials terminology when speaking about materials
• ensure the use of approved drawing equipment as outlined in the Equipment for specific HSC exams to maximise performance on all drawing questions across the examination.

Question 21

In better responses, students were able to:

• describe the testing process clearly, or identify a suitable device used to show changes in signal strength over time, describe its function, determine what the device can do in relation to the test, and recognise that the question refers specifically to wired or fibre-optic cabling, rather than wireless transmission media (a)
• recognise that aluminium cables must be lightweight and strong in tension to span distances between towers, and describe key mechanical and electrical properties of aluminium alloys, explaining how tensile strength influences their ability to span tower gaps (b)
• show that a network uses multiple towers or satellites, briefly summarise all required stages of modulation, conversion to digital, and demodulation, recognise that the phone performs modulation, clearly label the required diagram, explain how voice is converted to and from electrical radio signals, and accurately describe the roles of base stations and telecommunication towers (c)
• discuss a relevant modern telecommunications innovation by outlining multiple features, discussing their relationships, and presenting both positive and negative impacts on people’s lives (d).

Areas for students to improve include:

• correctly identifying and describing the applicable cabling-testing device by name and linking the response specifically to cable testing (a)
• explaining how aluminium’s tensile strength and weight affect how aluminium cables hang and sag between towers, relate each mechanical property to its real-world effect, compare aluminium to copper, including in terms of cost and suitability for long-distance cabling, and focusing on the wire itself, rather than the towers (b)
• demonstrating clear understanding of modulation, demodulation, digital conversion and transmission methods, recognise the stages of a communication network and how each section connects, explain how voice is converted to and from radio signals, recognise that an electromagnetic signal (and not sound) travels through the network, and produce a correctly labelled sketch showing essential features, rather than a flowchart (c)
• discussing the positive and negative impacts of a modern telecommunications innovation by linking each impact directly to its effect on people’s lives and focusing on relevant verbs, avoiding descriptions or historical context, and recognising that the question asks for human consequences, rather than explanations of how the innovation works (d).

Question 22

In better responses, students were able to:

• identify a specific building material and outline methods used for recycling materials when civil structures are replaced (a)
• provide characteristics and features of a suitable non-destructive testing procedure for detecting surface cracks in a single steel component, describing the step-by-step process from start to finish and distinguishing non-destructive testing methods used for surface crack detection from those used for sub-surface defect detection (b)
• calculate the shear stress for one bolt correctly by identifying the appropriate shear area, using the correct area formula in the shear stress equation, and showing clear and sequential working out to demonstrate progress in the calculation (ci)
• determine if the bolt can safely support the load by comparing allowable stress to the shear stress, calculating a factor of safety correctly, comparing it to the given 2.5 factor of safety, and providing clear recommendations that reflect all calculated work (cii).

Areas for students to improve include:

• identifying a specific product or material, for example, steel I-beams, aluminium window frames, copper wiring, tempered glass, and outlining the correct recycling method and processes using simple, specific examples (a)
• selecting a non-destructive test suitable for a surface crack rather than a sub-surface crack to show awareness of current innovations for detecting surface cracks, and provide relevant information that identifies the chosen test as appropriate, including how it is conducted and multiple characteristics or features of the method (b)
• calculating shear stress for each bolt by dividing the 30 kN load by three, substituting the given values into the appropriate shear-stress formula from the formulae page, recognising that only one shear area is required, and accurately applying the circular area formula (ci)
• relating yield stress, shear strength and allowable stress without confusing them with load or factor of safety, providing an informed recommendation and presenting calculations logically with appropriate magnitudes and units (cii).

Question 23

In better responses, students were able to:

• indicate that the role of mechanical advantage is to reduce the effort required by using winches, for example, how velocity ratios relate to increased distance thereby altering the required effort, or how gears can be used to change the direction of forces applied (a)
• indicate the importance of hardening the teeth of the gears to reduce wear while maintaining internal toughness to resist impacts
• relate the role of carbon in heat treating steel, that is, carburising is a method of surface hardening that increases the carbon content of the surface of the gear (b)
• apply graphical methods using the angle of static friction to produce a three-force vector diagram, or calculate the magnitude of the force required by using trigonometry and/or a scaled diagram, or calculate the minimum force required by using simultaneous equations related to the sum of the forces of a system in equilibrium (ci)
• calculate efficiency by finding the mechanical advantage of the inclined plane, recognising that the load is equal to the weight of the boat and using the effort calculated in part (c) (i) (cii).

Areas for students to improve include:

• expressing the function of gears in a winch as a mechanical device that changes the direction or magnitude of a force (a)
• providing an outline of the function of the gears in a winch, rather than a simple description of a winch system (a)
• selecting a suitable heat treatment method, rather than, for example, tempering, which is typically not suitable for mild-carbon steel (b)
• outlining the heat treatment method, rather than providing details of properties or suitability (b)
• recognising the need to calculate the difference in the angle of force in the winch cable and the angle of the inclined plane as 10° when analysing forces parallel and perpendicular to the inclined plane (ci)
• checking calculations for errors, for example, when using fractions to divide the mechanical advantage by the velocity ratio (cii).

Question 24

In better responses, students were able to:

• outline a number of key properties of Kevlar that are beneficial to aircraft, for example, lightweight, high tensile strength, non-corrosive, tough and/or impact resistant (a)
• describe that a stall is caused when the airflow over the aerofoil becomes turbulent and disrupted and this results in a loss of lift force, and relating this to conditions that may lead to this disrupted airflow (b)
• describe the operation of a mechanical altimeter referring to key aspects, for example, the comparison of sea level pressure to the hydrostatic pressure at the pitot tube causing it to change with altitude and activate a mechanical linkage connected to the instrument display, and support the response with a sketch of a mechanical altimeter (c)
• draw the front view of an orthogonal drawing to AS 1100 standards at the specified scale, and include two overall dimensions and appropriate hidden detail (d).

Areas for students to improve include:

• using correct engineering terminology to outline why Kevlar is a suitable material for this application (a)
• recognising that stalling is caused by a loss of lift due to disrupted airflow and that a number of factors can lead to this occurring (b)
• using the correct terminology and types of pressure relevant to an altimeter, for example, hydrostatic pressure (c)
• analysing the drawing and its dimensions carefully to ensure it is drawn to the correct proportions (d)
• applying orthogonal drawing and dimensioning standards to the drawing (d).

Question 25

In better responses, students were able to:

• identify the key steps of placing a mixed powder into a mould, compressing and then transferring the compressed form to be heat treated (a)
• highlight key considerations such as production off-site or on-site, the ability to re-tension post-tensioned beams and the disruption to the work site (b)
• clearly state the function of a capacitor in a full wave rectification circuit, sketch detailed graphs showing the waveform produced from the three circuits and correctly identify half-wave and full-wave rectification (c).

Areas for students to improve include:

• identifying the key stages in powder forming (a)
• recognising the benefits of both pre-tensioned and post-tensioned beams (b)
• identifying the correct function of a capacitor (c).

Question 26

In better responses, students were able to:

• list multiple advantages of collaboration (a)
• list advantages of steel beams, particularly strength, and relate these to effects on people’s lives, for example longer spans, improved transport and lower cost of goods (b)
• section the truss through member M and solve using the right-hand side of the truss, and then sum the vertical forces including the vertical component of M (c).

Areas for students to improve include:

• focusing on the collaborative work practices relating to a specific construction project (a)
• linking relevant properties of steel beams to the effect on people’s lives (b)
• analysing the forces on the truss and finding the reactions at supports before attempting to find M using method of sections or method of joints (c).

Question 27

In better responses, students were able to:

• describe ethical concerns caused by security camera systems in society (a)
• understand the process of artificial age hardening, by describing the process through the phases of heating (homogeneous structure), quenching (trap atoms) and heating moderately to allow for fine precipitates to form within the lattice (b)
• interpret true lengths from the orthogonal drawing correctly to appropriately construct a half pattern development (c).

Areas for students to improve include:

• linking ethical issues to their broader significance, such as privacy, individual rights, security and data protection (a)
• focusing on the heat treatment of aluminium (non-ferrous) alloys rather than the heat treatment of ferrous alloys, for example, steel (b)
• recognising that true length lines assist in the construction of half pattern development (c).