Electrotechnology 2021 HSC exam pack

Students should:

• read the question carefully to ensure that they do not miss important components of the question
• have a clear understanding of key words in the question and recognise the intent of the question and its requirements
• use the first page of the answer booklet for an extended response to develop a plan to assist in the logical sequencing of information
• engage with what the question is asking rather than presenting a pre-prepared response
• relate to the question throughout the response rather than just at the beginning
• ensure each extended response answer is completed in a separate writing booklet
• demonstrate knowledge and understanding of the examinable units of competency from the syllabus
• communicate ideas and information using relevant workplace examples and industry terminology
• be prepared to address a range of industry issues
• demonstrate knowledge of employability skills relevant to various situations
• include relevant annotations when including a diagram
• present a logical and cohesive response that answers the question
• review their response to ensure that it addresses the question requirements.

Question 16(a)

In better responses, students were able to:

• use correct industry terminology for electrical devices, for example, a socket outlet
• identify a safety switch, circuit breaker (CB) and residual current device (RCD or RCBO).

Areas for students to improve include:

• correctly identifying electrical industry components
• gaining experience in using common electrical equipment, such as switched socket outlet
• identifying commonly used electrical components such as circuit breakers (CB) and residual current circuit breaker with overload protection (RCBO).

Question 16(b)

In better responses, students were able to:

• identify that the device power lead and plug needs to be inspected for damage
• state the circuit breaker on the device needs to be tested for correct operation
• indicate the device needs to have be tested and tagged.

Areas for students to improve include:

• understanding the need to visually check all parts of electrical equipment for damage
• identifying all appliances need to be regularly tested and tagged
• recognising circuit breakers and safety switches need to be regularly checked for correct operation.

Question 17(a)

In better responses, students were able to:

• identify the switch as being an intermediate switch
• outline that the switch ‘S2’ allows the lights to be operated from all switch locations.

Areas for students to improve include:

• understanding the mechanical working parts of different light switches
• understanding the difference between a standard light switch and an intermediate switch
• knowing how to connect wiring and associated switches to a 3-way switching configuration
• understanding schematic diagrams (circuit diagram) and their components.

Question 17(b)

In better responses, students were able to:

• convert a circuit diagram to a wiring diagram
• correctly connect a fuse for circuit protection
• demonstrate knowledge that an active conductor must be switched which can be looped at the light or at the switch
• know the difference between a wiring diagram and a circuit or schematic diagram
• correctly locate the active, neutral and earth connections at a batten holder
• identify that the lamps are connected in parallel.

Areas for students to improve include:

• identifying that a fuse or equivalent is required for circuit protection
• demonstrating an understanding of how a switch works
• knowing the difference between how a switch mechanism works in comparison to an intermediate switch
• demonstrating an understanding of the difference between a circuit diagram and a wiring diagram
• demonstrating how to convert a circuit diagram to a wiring diagram
• understanding how active, neutral and earth conductors are connected at light switches and light fittings.

Question 18(a)

In better responses, students were able to:

• state the need to use a hammer drill when drilling into a masonry or brick wall
• demonstrate an understanding of the need to use a masonry or tungsten tip drill bit when drilling into masonry or brick walls.

Areas for students to improve include demonstrating:

• understanding of the hammer function on power drills
• knowledge in different types of drill bits and their application.

Question 18(b)

In better responses, students were able to:

• demonstrate an understanding of the process of completing the task in a logical order
• list the correct procedures for setting up the work site, marking out and levelling the bracket
• correctly identify suitable PPE, for example, safety glasses, hearing protection, dust mask
• correctly identify techniques and examples of fixing the bracket to the brick wall, for example, using dyna bolts.

Areas for students to improve include:

• demonstrating knowledge of the process of drilling into masonry and brick walls
• demonstrating an understanding of the logical process of carrying out practical tasks
• naming correctly associated tools and correct sizes of required materials and components to secure a 20kg item
• recognising the need for correct PPE to be used.

Question 19(a)

In better responses, students were able to:

• identify increasing energy storage in batteries during daylight hours provides electrical power at night-time and as a back up
• demonstrate a knowledge of the ability for batteries to store excess energy to be used later.

Areas for students to improve include:

• demonstrating a clear understanding of battery systems for energy storage to enable ‘off grid’ installations
• demonstrating an understanding of the relationship between solar panels and batteries
• recognising radiant energy can be stored in batteries and can be used when solar panels are not generating energy, for example at night-time.

Question 19(b)

In better responses, students were able to:

• provide a variety of strategies to reduce the carbon footprint on the farm, for example, using energy audits, using energy efficient lighting and energy efficient appliances
• suggest examples of alternate power generation, such as wind turbines, methane, hydro and biofuel power generation
• demonstrate an understanding of the use of electricity control systems, for example, timers and sensors on lighting and appliances
• state the need to reuse and recycle waste materials.

Areas for students to improve include:

• demonstrating a clear understanding of what is required to reduce a carbon footprint by using energy audits, the use of energy efficient lighting and appliance control systems
• discussing additional methods of generating electricity, such as, wind turbines, methane, hydro and biofuel power generation
• recognising that installing additional solar panels and battery banks would increase the farms capacity to store electrical energy to be used later
• demonstrating a knowledge of the reuse and recycling of waste and pre-used materials.

Question 20(a)

In better responses, students were able to:

• provide answers using the correct units
• demonstrate a knowledge of the relationship between series and parallel connected resistances
• use and provide the correct equations to determine the resistance value of series and parallel connected resistances.

Areas for students to improve include:

• providing answers using the correct units
• demonstrating knowledge in the step-by-step process of determining the total resistance of a given circuit
• understanding the relationship of series and parallel connected resistances
• knowing the correct equation to determine resistances in a series circuit and a parallel circuit.

Question 20(b)

In better responses, students were able to:

• provide answers using the correct equations
• apply Ohm’s Law to solve problems in series and parallel circuits
• demonstrate their understanding in substituting values of resistance and voltage into the correct equation to determine current flow
• demonstrate knowledge and understanding of voltage drop in each circuit.

Areas for students to improve include:

• using the correct units
• demonstrating an understanding of a working circuit diagram
• identifying the correct electrical symbols used in a circuit diagram
• understanding how to substitute correct values of resistance, voltage and current into Ohm’s Law to determine related values
• providing the correct equation.

Question 20(c)

In better responses, students were able to:

• provide answers using the correct units
• demonstrate knowledge and understanding of current flow in a given circuit
• identify the correct values of current flowing through various parts of a working circuit
• use Ohm’s Law to calculate voltage drop across specific circuit components
• provide the correct equation.

Areas for students to improve include:

• understanding the correct electrical units
• knowing how to identify current flow through different parts of a circuit
• applying Ohm’s Law to calculate voltage drop across a circuit component
• knowing that a voltage drop exists across individual circuit components
• understanding how to apply the correct equation to determine voltage drop.

Question 20(d)

In better responses, students were able to:

• provide answers using the correct units
• identify the correct value of current flowing through R4
• substitute the correct value of current and resistance using the correct power equation
• provide the correct equation.

Areas for students to improve include:

• understanding the correct units for power equations
• using power equations to determine the power dissipated by circuit components
• understanding how current flows in series connected circuit components
• knowing the relationship power has to circuit current and resistance
• understanding the correct use of power equations.

In better responses, students were able to:

• explain the role that management has in preventing and responding to managing workplace injuries
• discuss that management must provide training, policies and workplace procedures that relate to legislation and standards
• explain the role that workers have in the prevention, response to and management of workplace injuries
• discuss that workers must follow workplace policies and procedures
• demonstrate an understanding that both management and workers have in dealing with injuries relating to working from heights, trips, falls, being hit by objects, lifting and pushing or pulling objects
• demonstrate understanding by stating a range detailed practical examples of responses to workplace injuries relating to working from heights, trips, falls, being hit by objects, lifting and pushing or pulling objects
• use correct industry terminology relating to management and worker responsibilities.

Areas for students to improve include:

• discussing the role of management in the prevention of workplace injuries
• demonstrating knowledge of the legal responsibility that management has in relation to the prevention, response and management of workplace injuries
• discussing the role of workers in the prevention of workplace injuries
• explaining the role of management and workers by stating examples and the responses to injuries that may occur when working at heights, trips, falls, being hit by objects, lifting and pushing or pulling objects
• using specific Electrotechnology terminology and definitions.

Question 22(a)

In better responses, students were able to:

• demonstrate an understanding of the correct process to de-energise and isolate a power circuit
• state the need for workplace communication before isolating power to a circuit
• state the need to identify the circuit to be isolated
• discuss the importance of testing the test equipment to ensure safety is maintained
• recognise the need to ‘lock out and tag’ the circuit breaker or fuse when a power circuit has been de-energised
• recognise the need to double check that power has been isolated
• recognise the need to retest the test equipment on a known power supply.

Areas for students to improve include:

• recognising the need to follow a step-by-step process in de-energising and isolating a power circuit at a switchboard
• demonstrate understanding in the need to notify people that power is about to be isolated (workplace communication)
• knowing that the correct power circuit needs to be identified before work can be carried out
• recognising the importance of making sure that the test equipment, multimeter or test lamps, is tested to ensure correct operation
• understanding the need to ‘lock out and tag’ the circuit breaker or fuse to make sure that the power is not turned back on when work is in progress
• recognising the need to double check that the power has been successfully isolated
• recognising the need to retest the test equipment on a known power supply.

Question 22(b)

In better responses, students were able to:

• demonstrate a logical fault-finding process to determine the type of fault causing the power circuit to trip
• discuss the need to visually check the switchboard and associated wiring and equipment for damage or for the ingress of water
• discuss the process of checking the power circuit for condition (earth leakage) by carrying out an insulation resistance check using an insulation resistance tester or ‘megger’
• demonstrate knowledge in using an ohm meter to check the power circuit for circuit continuity or measuring the resistance between the active and neutral wires
• discuss checking the circuit protection device for correct operation, for example, by measuring current flow using a ‘tong’ or ‘clamp’ ammeter.

Areas for students to improve include:

• demonstrating the need to systematically fault find by going through a sequential process to determine the fault
• understanding how to use a variety of test equipment to determine an electrical fault, which include an insulation resistance tester, ohm meter and ammeter
• recognising the need to visually check circuit wiring, appliances and switchboard for signs of damage caused by heat, rodents or water ingress
• understanding the testing processes for insulation resistance, continuity, resistance current measurement.