Electrotechnology 2015 HSC exam pack (archive)

Candidates showed strength in these areas:

• identifying ways of minimising waste, such as accurately measuring and ordering the required materials (Q.16)
• recognising the importance of forward planning (Q.16)
• understanding that a schedule of work may include work tasks, tools required and start and finish times for the tradesperson (Q.17)
• identifying the need for safe work method statements when certain tasks require a higher level of safety (Q.17)
• recognising components in a circuit (Q.18 (a))
• drawing a circuit diagram (Q.18 (b))
• selecting a suitable fixing method for mounting a weatherproof outlet onto a wall (Q.19 (a))
• addressing the requirements in the scenario by outlining the correct sequence of installation steps (Q.19 (b))
• demonstrating understanding of electrical requirements, such as the need for isolation, lockout and tagging, and the need for circuit protection (Q.19 (b))
• calculating the resistance of R (Q.20 (a))
• recognising that the circuit current will split between the two paths in the circuit and the reduced current through resistor R will be used to calculate the true value of R (Q.20 (b))
• recognising that the circuit consisted of a combination of parallel connected resistors and series connected resistors (Q.21 (a))
• adding equivalent parallel resistances to series resistors (Q.21 (a))
• performing multiple and submultiple calculations (Q.21 (b))
• performing an Ohms law calculation using full circuit current and the equivalent value resistance of resistors R₅and R₆ to calculate voltage drop across resistor R₅ (Q.21 (c))
• selecting the correct power formula (Q.21 (d)).

Candidates need to improve in these areas:

• understanding the difference between the energy sector and saving energy (Q.16)
• consideration of risk management and communication methods (Q.17)
• identifying team meetings, supervisor instructions and reporting requirements as part of a schedule of work (Q.17)
• using appropriate industry terminology, eg not referring to component Q as a power board (Q.18 (a))
• showing correct connections, eg for the ammeter in series to measure the current through R₁, the voltmeter in parallel to measure the voltage across R₃ (Q.18 (b))
• showing correct polarity of the ammeter and the voltmeter (Q.18 (b))
• justifying their choice of fixing method (Q.19 (a))
• understanding the need to comply with wiring rules AS3000:2007 (Q.19 (b))
• understanding the effect of the voltmeter in the circuit on calculating the true value of R (Q.20 (b))
• selecting appropriate formulas to calculate equivalent resistance (Q.21 (a))
• using the correct Ohms law formula to calculate total circuit resistance (Q.21 (a))
• using I = V/R instead of I = R/V (Q.21 (b))
• recognising that the total circuit current passes through R₄ (Q.21 (b))
• using correct units (Q.21 (c))
• performing correct substitution or multiple or submultiple calculations (Q.21 (c) and (d)).

Candidates showed strength in these areas:

• demonstrating knowledge of first aid, CPR and the DRSABCD method
• recognising the need for isolation before giving assistance
• recognising the need for risk assessment in repair work involving working at heights.

Candidates need to improve in these areas:

• recognising retraining and education, reporting of accident to WorkCover, review of Safe Operating Procedures, rehabilitation of worker and compensation as possible long-term actions.

Question 23(a)

Candidates showed strength in these areas:

• selecting the installation of such things as energy efficient light fittings, solar panels, solar hot water and gas hot water systems, skylights, larger windows for light and natural ventilation, time switches and recycling old fittings if possible.

Candidates need to improve in these areas:

• justifying how these items can work together as a more complex system to minimise energy usage
• using industry terminology.

Question 23(b)

Candidates showed strength in these areas:

• describing the procedure, identifying the hazards and naming controls for a safe work method statement (SWMS)
• identifying that the job involves working at heights and suggesting appropriate use of equipment, such as scaffolding, scissor lifts and harnesses
• identifying the possibility of recycling old fittings where applicable.

Candidates need to improve in these areas:

• considering all aspects of the question
• providing more detail in procedures
• recognising that in the scenario the school hall is a construction site and appropriate signage, barricades and PPE should be included as part of a SWMS.