Electrotechnology 2019 HSC exam pack (archive)

 Students should:

• know and understand the use of common tools, equipment and materials relating to the electrotechnology industry
• be able to apply Ohm’s Law and power equations to a given circuit
• understand how to determine voltage drop across circuit components
• understand wiring diagrams and recognise how electrical circuits function
• determine how electric circuit components are arranged to achieve a given scenario
• be aware of sustainable work practices that will contribute minimising environmental impacts
• demonstrate knowledge of alternate methods and technologies used in the generation and production of electrical power
• be able to identify natural resources that are available for the production of electricity.

Question 16(a)

In better responses, students were able to:

• describe TPS cables as having an outer sheath with TPI cables being inside a sheathed cable
• explain the construction of single insulated cables, for example, building wires are made of copper with one layer of insulation
• understand the construction of double insulated cables
• understand that conductors can have several layers of insulation.

Areas for students to improve include:

• knowing and understanding electrical cable terminology
• understanding that electrical cables vary their layers of insulation
• knowing the construction of a single and a double insulated conductor.  

Question 16(b)

In better responses, students were able to:

• identify how to correctly isolate electricity
• discuss the process in removing the outer sheath of a cable
• list the tools required to remove cable insulation, cut to length and terminate in a socket outlet
• understand how to terminate electrical cables in an appliance.

Areas for students to improve include:

• identifying how to correctly isolate electricity using the lock out and tag method
• knowing and understanding industry terminology in the electrotechnology field, for example, being able to identify a socket outlet
• explaining the step by step process in removing the insulation of electrical cables using the correct tools
• recognising that copper conductors need to be terminated securely in a socket outlet terminal.

Question17(a)

In better responses, students were able to:

• demonstrate an understanding of circuit symbols and components
• understand how resistance changes with different circuit configurations
• calculate resistances in combined series and parallel circuits
• understand that a fuse is located as close to the supply as possible.

Areas for students to improve include:

• knowing the relationship that circuit components have with other components
• developing an understanding of calculating resistance in series and parallel circuits.
• correctly locating electrotechnology components with a given circuit.

Question 17(b) 

In better responses, students were able to:

• demonstrate a step by step process for finding faults in a circuit
• determine the correct use of a multimeter when fault finding
• list the steps involved in checking individual circuit components for correct operation.

Areas for students to improve include:

• understanding industry terminology in relation to fault finding, for example, continuity, open circuit, closed circuit
• systematically working through a circuit using a fault-finding procedure
• demonstrating knowledge in the correct use of a multimeter for measuring circuit voltage
• knowing how to use a multimeter to check individual circuit components either by using a continuity tester (Ohms) or voltmeter.

Question 18(a)

In better responses, students were able to:

• determine the purpose of each switch
• identify the that S1 is a master switch
• state that S2 and S3 form two way switching
• explain how switching configurations operate the light.

Areas for students to improve include:

• understanding how a switch works
• ability to read a wiring diagram
• knowing and understanding two way switching
• understanding lighting control circuits.

Question 18(b)

In better responses, students were able to:

• know how to test a multimeter for correct operation
• identify the steps required to isolate power
• recognise that other people are affected when power is turned off.

Areas for students to improve include:

• using industry terms relating to isolation procedures
• completing the step by step process to isolate electricity
• stating the impact that work has on surrounding people / trades
• knowing the importance of ensuring that test equipment is working correctly.

Question 19

In better responses, students were able to:

• recognise and explain the danger of electricity
• clearly apply the steps in DRSABCD
• use an appropriate method to remove a person in contact with electricity, for example, by using a plastic hook or other insulated material.

Areas for students to improve include:

• applying the steps DRSABCD to a situation
• stating the dangers of electricity
• stating the effects that electricity has on the human body
• demonstrating a clear understanding of strategies in treating a person from possible electrocution.

Question 20(a)

In better responses, students were able to:

• correctly state and use the formulae for determining resistance in a parallel circuit and substitute values correctly
• recognise series connected components and determine equivalent resistance.

Areas for students to improve include:

• identifying series connected resistances
• recognising when series connected resistances combine and substituting these values into the formulae used to determine total resistance.

Question 20(b)

In better responses, students were able to:

• state the correct formulae and substitute correctly
• identify the various steps required to determine current flow in a parallel circuit
• apply Ohm's Law to solve problems
• determine voltage drop in various parts of an electrical circuit.

Areas for students to improve include:

• knowing the correct units of electricity, for example, ‘current (I)’ is measured in ‘amperes (A)’
• understanding and apply Kirchoff’s voltage law
• applying Ohm’s Law to solve problems
• understanding current flow in series and parallel circuits.

Question 20(c)

In better responses, students were able to:

• state the formulae required to determine power in circuit components and substitute correctly
• recognise that the voltage drop across a circuit component is used to determine the power dissipated by that component
• identify the current flowing through a specific component.

Areas for students to improve include knowing:

• the three formulae used to determine power
• the correct units of electricity, for example, ‘current (I)’ is measured in ‘amperes (A)’, power (P) is measured in watts
• and understanding the correct values to use when calculating power.

Question 20(d)

In better responses, students were able to:

• state the correct formulae for determining the time constant
• use the correct unit of measurement for time.

Areas for students to improve include understanding:

• capacitors and how they work
• correct conversation of multiples and submultiples.

Question 20(e)

In better responses, students were able to:

• show that five time constants are required to charge one capacitor.

Areas for students to improve include:

• understanding capacitors and how they work
• recognising that it takes five time constants for a capacitor to fully charge.

In better responses, students were able to:

• demonstrate an understanding of the difference between work, health and safety (WHS) inductions and policies
• list types of WHS inductions by providing examples
• list types of WHS policies by providing examples
• explain how inductions and policies contribute to a safer workplace by preventing injuries
• make specific reference to the emotional wellbeing of workers
• explain that a safer workplace results in being a more productive workplace.

Areas for students to improve include:

• using relevant terminology rather than providing generalised information
• recognising that WHS inductions and policies are two distinct areas for consideration
• demonstrating a clear understanding of the safety needs associated with workplaces
• understanding that the implementation of WHS inductions and policies lead to a safer workplace
• using specific workplace examples of induction training
• using specific workplace examples of WHS policies
• identifying that a safer workplace leads to  greater productivity and workplace efficiency.

Question 22(a)

In better responses, students were able to:

• identify that various products or items can emit harmful greenhouse gases into the atmosphere during its lifetime or during its production
• that harmful gases emitted into the atmosphere cause lasting damage
• list contributing factors to creating ‘carbon footprint’ such as carbon dioxide.

Areas for students to improve include:

• expressing an understanding for causes of ‘carbon footprint’
• understanding what carbon emissions include
• listing the harmful emissions that create a lasting negative impact on the environment.

Question 22(b)

In better responses, students were able to:

• define the term ‘audit’
• list the factors involved in determining an energy audit including energy consumption and waste disposal
• recognise that an energy audit should be conducted at peak times of the day
• know that specialised equipment is required to conduct an energy audit.

Areas for students to improve include:

• understanding specific course terminology and definitions, for example, understanding the term ‘energy audit’
• recognising that specific processes need to be followed in conducting an energy audit
• knowing that particular appliances require special considerations in relation to energy consumption.

Question 22(c)

In better responses, students were able to:

• articulate that energy demands can be reduced by introducing alternate methods of producing and storing electrical energy
• list a variety of methods of generating electricity
• identify a variety of energy saving appliances that minimise energy demands
• discuss that building design can use natural methods for heating and cooling purposes and by using natural light convection
• implementation of sustainable work practices for example, waste reduction and recycling programs.

Areas for students to improve include:

• understanding and using specific course terminology and definitions
• identifying that there are a number of alternate means of energy production, for example, solar and wind
• understanding that electrical appliances are becoming more energy efficient
• recognising that building design can reduce energy consumption
• identifying specific strategies and sustainable work practices required to reduce energy demands, for example, by installing timers and sensors.