Megawatt Teacher Notes
Acknowledgments
The school-based activities included in this education kit were developed
by a team of Education Officers at Scienceworks Museum (Museum
Victoria) and other educators.
The support of the Department of Education, Employment and Training
and the Catholic Education Office is acknowledged.
This education kit is based on the Sparks education kits
published in 1995. Revised May, 2008.
Last revised October 2012 (By Bronwyn Quint).
Project leader
Peter Pentland
Writing team (1995)
Lindy Bok, David Demant, Chris Hourigan and Pennie Stoyles
Additional writers
Patricia Christies, Peter Pentland, Pennie Stoyles and Bronwyn Quint
Illustrators
Chris Hourigan, Richard Glover and Rodney Pike
Designer
Luisa Laino
© Museum Victoria 2012
ISBN 0 7311 7224 8
Scienceworks
2 Booker Street
Spotswood, Victoria 3015
www.museumvictoria.com.au/education/
Teachers may photocopy the contents of this kit for educational purposes.
Scienceworks
Education bookings: telephone 03 9392 4819 weekdays 8.30am – 4.30pm
http://museumvictoria.com.au/scienceworks/education/
http://museumvictoria.com.au/scienceworks/education/education-programs/megawatt/
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Megawatt Teacher Notes
Contents
Introduction ......................................................................................................................................... 4
Essential preparation ........................................................................................................................ 5
Megawatt exhibition information ................................................................................................... 6
Curriculum links for the Megawatt education kit....................................................................... 7
AUSVels Science Understanding .................................................................................................. 9
Word List for Teachers ................................................................................................................... 10
Static electricity ................................................................................................................................ 13
Activity 1: Static experiences ............................................................................................................ 14
Activity 2: Hundreds and thousands ............................................................................................... 14
Activity 3: Boat races ......................................................................................................................... 15
Activity 4: Shocking facts about lightning ....................................................................................... 16
Cells and batteries........................................................................................................................... 17
Activity 5: Lemon battery................................................................................................................... 18
Activity 6: Voltaic piles ....................................................................................................................... 19
Activity 7: Battery life ......................................................................................................................... 20
Electric circuits................................................................................................................................. 21
Activity 8: Conductors and insulators ............................................................................................. 22
Activity 9: Role-play a circuit ............................................................................................................ 24
Activity 10: Switches and circuits .................................................................................................... 26
Activity 11: Appliance science .......................................................................................................... 27
Activity 12: Electric jug ...................................................................................................................... 29
Activity 13: Invent an appliance ....................................................................................................... 29
Activity 14: Electrical safety .............................................................................................................. 30
Activity 15: Check your electricity use ............................................................................................ 32
Activity 16: Electrical safety at home .............................................................................................. 32
Activity 17: Life without electricity.................................................................................................... 33
Electromagnets and electric motors .......................................................................................... 34
Activity 18: A simple electromagnet ................................................................................................. 35
Activity 19: An electromagnet with a switch................................................................................... 37
Activity 20: Dancing dolly .................................................................................................................. 38
Activity 21: Vibrating light globes ..................................................................................................... 39
Activity 22: Simple electric motors .................................................................................................. 40
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Megawatt Teacher Notes
Generators ......................................................................................................................................... 41
Activity 23: Do-it-yourself generator ................................................................................................ 42
Activity 24: Power to the people ...................................................................................................... 43
Sustainable energy .......................................................................................................................... 44
Activity 25: Photovoltaic cell ............................................................................................................. 45
Wind or water turbines ................................................................................................................... 46
Activity 26: Make a pinwheel............................................................................................................ 46
Activity 27: Electricity time-line ........................................................................................................ 48
Biographies ....................................................................................................................................... 49
Resources .......................................................................................................................................... 52
Visit Activities
Activity set A - Years 3 – 5 ................................................................................................................ 54
Activity set B - Years 5 – 8 ................................................................................................................ 58
Activity set C - Yeas 9 – 10 and VCE Physics ............................................................................... 62
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Megawatt Teacher Notes
Introduction
Megawatt is a multi-media exhibition that explores the role of electricity
in everyday lives. It features interactive exhibits.
The purpose of the kit is to assist teachers to prepare for a visit to the
Megawatt exhibition and to provide them with school-based activities to
further explore the concepts introduced in the exhibition.
The Megawatt education kit has been written for teachers and students
in Years 3-10 and VCE Physics. It supports the Megawatt exhibition at
Scienceworks museum from 14 February to 23 August 2013.
The writers have assumed that primary students have no prior
knowledge of electricity and secondary students have had some prior
experience in the topic area. Procedure, report and explanatory text
types have been included to enable teachers to enhance the scientific
literacy of students.
The science concepts explored in this education kit are static electricity,
the construction of a cell, electrical safety, energy transformations, the
function and use of electrical appliances, electromagnetism, electric
circuits and alternating and direct current.
The kit contains:
• excursion activities:
suggested activities that may be completed during a visit to the
Megawatt exhibition
• school-based activities
divided into topic areas that can be completed before or after the
visit. Selected activities are supported by student worksheets that
are marked by the logo shown below
•
•
a word list for teachers to assist with the understanding
of concepts covered in the exhibition and the education
kit
background information sections of this kit
contain additional information for teachers. The
activities are directed to the teacher.
We encourage teachers to adapt these activities to meet the needs of their students
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Megawatt Teacher Notes
Essential preparation
What to do before you visit Megawatt
Research has shown that setting objectives for a museum visit is extremely
important for students. It makes the purpose of the visit clear to them and
assists their ability to focus and cooperate during the visit.
Creating interest in the subject is vital to a successful and enjoyable visit to
Scienceworks. This education kit contains suggestions for activities you
may choose to do prior to your visit.
Read the Medical condition caution below and assess whether this may
affect any of your students.
What to bring to your visit to Megawatt
•
•
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a copy of the confirmation email
students should bring their own pencils and clipboards
teachers should provide each student or group of students with a
photocopy of the appropriate activities that corresponds to the level
of their students.
Activity set (Yrs 3 - 5)
Activity set B (Yrs 5 - 8)
Activity set C (Yrs 9 - 10, VCE Physics)
Medical condition caution
This exhibition contains many electrical and magnetic fields.
Sudden loud noises also occur in this exhibition. Persons with any
of the following may be at risk:
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heart pacemakers
heart conditions
cochlear implants
hearing aids
other hearing problems
prostheses (including internal metal wires and pins)
and very young children.
We strongly suggest that persons who may be affected do not attend
the exhibition. If it is suspected that you or your students may be
affected please seek medical advice before visiting Scienceworks
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Megawatt Teacher Notes
Megawatt exhibition information
Your experience in the Megawatt exhibition lasts for one hour and is
supported by suggested student activities. The major communication
objective of Megawatt is safety when dealing with electricity. The
exhibition will be divided into seven colour coded modules. These are:
Module
Title
Colour code
Main module
Electricity is everywhere, in everything!
WHITE
Transport and Travel
Electricity takes us places!
GREEN
Entertainment
Electricity entertains us!
YELLOW
Household Uses
Electricity - safety at home!
PURPLE
Communication
Electricity for communication!
BLUE
Generation and Transmission Electricity - a controlled energy supply!
RED
Renewable Energy
ORANGE
Electricity - sustainable energy!
Each module has hands-on interactives to facilitate the learning of electricity concepts
relevant to that module.
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Megawatt Teacher Notes
Curriculum links for the Megawatt education kit
Static experiences
Hundreds and thousands
Boat races
Shocking facts about lightning
Lemon battery
Voltaic piles
Battery life
Conductors and insulators
Role-play a circuit
Switches and circuits
Appliance science
Electric jug
Invent an appliance
Electrical safety
Check your electricity use
Electrical safety at home
Life without electricity
A simple electromagnet
An electromagnet with a switch
Dancing dolly
Vibrating light globes
Simple electric motors
Do-it-yourself generator
Power to the people
Photovoltaic cell
Make a pinwheel
Electricity time-line
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Thinking
Information &
Communications
Technology (ICT)
Design, Creativity
& Technology
Communication
Science
Interdisciplinary Learning
Mathematics
Humanities
Languages Other
Than English
English
Discipline-based
Learning
The Arts
Civics &
Citizenship
Personal Learning
School-based education activities
Interpersonal
Development
Victorian Essential Learning
Standards
Physical, Personal & Social
Learning
Health & Physical
Education
VELS
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Megawatt Teacher Notes
Static experiences
Hundreds and thousands
Boat races
Shocking facts about lightning
Lemon battery
Voltaic piles
Battery life
Conductors and insulators
Role-play a circuit
Switches and circuits
Appliance science
Electric jug
Invent an appliance
Electrical safety
Check your electricity use
Electrical safety at home
Life without electricity
A simple electromagnet
An electromagnet with a switch
Dancing dolly
Vibrating light globes
Simple electric motors
Do-it-yourself generator
Power to the people
Photovoltaic cell
Make a pinwheel
Electricity time-line
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Intercultural
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Ethical behaviour
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Personal and social
capability
Critical and creative
thinking
Information &
Communications
Technology (ICT)
capability
Numeracy
General Capabilities
Literacy
Science
School-based education
activities
Discipline-based
Learning
Mathematics
AusVELS
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Megawatt Teacher Notes
AUSVels Science Understanding
Physical Sciences
Level 4
Forces can be exerted by one object on another through direct contact or from a distance
 Comparing and contrasting the effect of friction on different surfaces, such as tyres and shoes
on a range of surfaces.
General Capabilities
 Literacy
 Critical and creative thinking
 Numeracy
Level 6
Electrical circuits provide a means of transferring and transforming electricity
 Recognising the need for a complete circuit to allow the flow of electricity
 Investigating different electrical conductors and insulators
 Exploring the features of electrical devices such as switches and light globes
General Capabilities
 Critical and creative thinking
Level 9
Energy transfer through different mediums can be explained using wave and particle models
 Exploring how and why the movement of energy varies according to the medium through
which it is transferred
 Investigating factors that affect the transfer of energy through an electric circuit
General Capabilities
 Literacy
 Critical and creative thinking
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Megawatt Teacher Notes
Word List for Teachers
alternating current
A flow of electric current in which the direction of movement periodically changes.
The number of complete cycles in a second is called the frequency. In Australia, AC
current has a frequency of 50 cycles per second or 50 Hertz.
ammeter
An instrument which measures electric current.
ampere
The unit of measurement for electric current. It corresponds to the flow of
approximately 6 x 1018 electrons per second. Ampere is usually shortened to amps
or A.
arc
A brief flash of light caused by an electric current moving through a gas between
two points with a high voltage difference. An arc lasts much longer than a spark.
battery
A battery is a combination of cells connected together in series. Most car batteries
are made up of six separate cells.
capacitor
A pair (or pairs) of conductors separated by insulators. A capacitor stores electric
charge.
cell
A single device that changes chemical energy into electrical energy. It usually
consists of two electrodes and a conducting liquid called an electrolyte. Many
commonly used batteries (for example a D sized torch battery) more correctly
should be called a cell.
charge
An excess of electrons results in an object having a negative charge and a
deficiency of electrons results in an object having a positive charge. The unit of
measurement of charge is the coulomb (C). One coulomb is the amount of charge
carried by approximately 6 x 1018 electrons.
conductor
An object or substance through which electricity can flow easily.
current
The rate of flow of electrons. The symbol for current is I. Current is measured in
amperes (A).
direct current
A flow of electric current in one direction only. Batteries supply direct current (DC).
dry cell
A cell where the conducting liquid (electrolyte) is in the form of a paste or jelly so
that it doesn’t spill. The common torch battery is an example of a dry cell.
electricity
A general term for the phenomena associated with electrons at rest or in motion.
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Megawatt Teacher Notes
electrode
A conductor which allows electricity to flow in or out of a material or object.
Electrodes are usually made from a metal or graphite.
electromagnet
A coil of wire which only becomes magnetic when electricity passes through it. The
coil may be wound around a material such as iron to increase the magnetic effect.
electrolysis
A process where electricity is used to bring about a chemical change. For example,
electrolysis of sea water can be used to produce chlorine.
electrolyte
A liquid that conducts electricity. The liquid may be in the form of a paste or gel.
electron
A sub-atomic particle found in every type of atom. Electrons have a negative charge
and are found outside the nucleus of an atom.
galvanisation
An electrolytic process where iron objects are coated with a thin layer of zinc. This
reduces the rate at which the iron rusts.
galvanometer
An instrument which can be converted for use as a voltmeter or an ammeter.
generator
A machine which converts one form of energy into another. An electricity generator
converts kinetic energy into electrical energy.
insulator
An object or material that has a high resistance to the flow of electricity.
Leyden Jar
An old fashioned device for storing static electricity.
magnet
A piece of metal that exists naturally with a magnetic field surrounding it. This field
exerts a force on other magnets and iron pieces.
motor
A machine which converts electrical energy into kinetic energy.
ohm
The unit of measurement of the resistance to the flow of electric current in a circuit.
Ohm is often represented by the symbol Ω.
parallel circuit
A way of arranging wires and ‘appliances’ in a circuit The circuit is in parallel when
the current flowing has more than one pathway to flow through.
resistance
The tendency for materials to resist the flow of electric current and convert electrical
energy into heat. The unit of measurement for resistance is the ohm. The symbol for
resistance is R.
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Megawatt Teacher Notes
series circuit
A way of arranging wires and ‘appliances’ in a circuit. A circuit is in series when all
the parts are arranged end to end in a continuous path.
solar cell
A device for converting the Sun’s energy into electrical energy. A solar panel is
made up of many solar cells.
solenoid
A coil of wire which is usually wound around a tube. It is used to produce a
magnetic field (see electromagnet).
Spark
A brief flash of light caused by an electric current moving through a gas between
two points with a high voltage difference. A spark lasts for a very short time.
static electricity
Electric charge acquired by an object as a result of being rubbed, being brought
close to, or touching another charged object.
transformer
A device used to alter voltage or (alternating) current. They work without moving
parts by the process of electromagnetic induction.
Volt
A unit of measurement of voltage. Voltage is a measure of the amount of electrical
energy available. The symbol for volt is V.
voltmeter
An instrument which measures voltage.
Watt
The unit of measurement of power. In electrical systems it is the number of amps
multiplied by the number of volts. The symbol for watt is W.
Wet cell
A cell where the electrolyte is in the form of a liquid. This means that they must be
kept upright to avoid spillage. Most car batteries are wet cells.
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Megawatt Teacher Notes
Static electricity
Background information
You may be familiar with getting zapped while getting out of a
car, zapping yourself or someone else after walking on
carpet. All these incidents involve static electricity. When you
rub certain materials together, you can set up a charge. If the
static electricity is strong enough, you can see and/or hear a
spark moving from one object to another as it discharges.
Discharging occurs when the charged object loses its
electricity to another object on the Earth.
There are two types of charge, positive charge and negative charge.
• when two materials have the same charge (positive
and positive or negative and negative), they repel
each other
• when two objects have different charges (positive and
negative and vice versa) they attract each other
• charged objects attract neutral objects (objects that have no charge).
If an object is charged, it will discharge by coming in contact
with or close to the Earth either directly or indirectly. For
example, a charged rod will discharge through the Earth via
the human body when it comes in contact with a human
finger. The charge is given a pathway to the Earth via the
person's finger. A strong charge can jump to the Earth
through the finger if it is close enough. The person may feel a
little shock as the rod discharges.
Lightning is a discharge of static electricity on a much larger scale.
Buildings have lightning rods that reach high in the sky so
that the charged clouds can discharge through them to the
Earth. This protects buildings by providing a safe path for the
electricity to pass through as it travels to the Earth.
Activities 1-4 relate to static electricity.
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Megawatt Teacher Notes
Activity 1: Static experiences
What to do
Students can list their daily encounters with static electricity. For example:
• pulling clothes out of the dryer
• touching door handles in a carpeted room
• getting out of the car
• taking off certain clothes
• emptying rice out of its plastic bag.
Students can compare their findings in small-group
discussion or by making a list for class display.
Activity 2: Hundreds and thousands
What you need
• ‘hundreds and thousands’
• shallow (l or 2 cm) container with a clear plastic lid
(e.g. a small take away food container)
• woollen clothing or cloth.
What to do
Ask your students to:
1 Put a small amount of ‘hundreds and thousands’ in the container.
2 Put the lid on the container and charge the lid by rubbing it with a
woollen cloth.
Observe what happens.
3 Gently move a finger over the top of the container and observe what
happens.
Questions
1 Why do the ‘hundreds and thousands’ often jump back down?
2 What happens when you move your finger over the top of the
container?
shallow container with clear plastic lid
‘hundreds and thousands’
Neutral spheres are attracted to the lid and
the charged ones are repelled.
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Megawatt Teacher Notes
Activity 3: Boat races
What you need
• corks
• plastic pens
• wool cloth or clothing
• large bowl of water.
What to do
Static electricity can be used to play a simple boat-race game.
1 Each player floats a cork ‘boat’ in the large bowl of water.
2 The boats are pushed under water so they come up wet.
3 Each player then charges up a plastic pen by quickly rubbing it on
the wool cloth or clothing.
4 Players then use their pens to pull the boats from one side of the bowl
to the other by placing the pen close to the wet cork (being careful not
to touch the cork or the water). The first cork/boat to touch the other
side of the bowl wins.
If the pen touches the wet boat or the surface of the water, the pen will
discharge and the boat will stop. The students may need to charge their
pens more than once during the race.
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Megawatt Teacher Notes
Activity 4: Shocking facts about lightning
What you need
A collection of reference books such as the Guiness Book of Records,
Latest Great Moments in Science, encyclopedias or access to the
Internet.
What to do
Ask the students to find out one or more amazing facts
about lightning. For example:
• How long is a lightning bolt?
• Can lightning’s energy be caught and stored?
• Big buildings get hit by lightning all the time, why don’t they burn
down?
• How many people are killed by lightning per year?
• What can you do to prevent yourself from being struck by lightning?
• Some people have been hit by lightning many times, why have they
survived?
• How many bushfires are started by lightning strikes?
• ‘Lightning never strikes twice in the same place.’ Is this a myth or a
fact?
Students can:
• compare their findings in small-group discussion or make a list for
class display
• write a fictional story using one or more of the amazing fact(s) found
through the research
• write a creative poem using the information researched
• write a song that explains how getting struck by lightning can be
prevented.
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Megawatt Teacher Notes
Cells and batteries
Background information
A cell is a single device that changes chemical energy into electrical
energy. A torch battery is actually a cell (in scientific terms). A battery is
a number of cells connected together in a particular way (in series). A
car battery is made up of at least six cells. In 1800, Allesandro Volta
(see page 50) made the first battery using the principle that two
different metals connected by certain liquids produce electricity. A simple
low-powered cell can be made using a lemon and two different metals. If
you wanted to make a 'battery' using lemons, one lemon would need to
be connected to another lemon with wires connecting alternate metals.
When a cell or battery is connected to a conductor, one end becomes the
positive terminal and the other end becomes the negative terminal. To
connect one cell in series with another cell, the positive terminal of one cell
should be connected to the negative terminal of the next cell.
Activities 5-7 relate to cells and batteries.
Lemon battery
Copper
zinc
lemon
Light globe
Conducting wire
Battery
Conducting wire
cell
Light globe
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Megawatt Teacher Notes
Activity 5: Lemon battery
What you need
• lemons
• small pieces of zinc
• small pieces of copper
• wires
• a voltmeter or multi-meter (switched to volt)
• small light globe.
What to do
Ask the students to:
1 Give a lemon a good squeeze, but be careful not to split the skin.
2 Connect one wire to one piece of zinc and push the metal into the lemon.
3 Connect another wire to a piece of copper and push the metal into the lemon.
4 Connect the wires to the voltmeter (see diagram).
5 Record the voltage created by the lemon cell.
6 Connect a light globe into the circuit in place of the voltmeter and record
what happens.
7 You may have found this current is too small to light a light globe.
Connect a number of lemons together as shown in the diagram until the
current is large enough to light the light globe. Record your results.
Questions
1 Is the voltage supplied by one lemon enough to light the light globe?
2 How many lemons did it take to light the light globe?
3 If you assume that each lemon supplies the same voltage, calculate
the voltage supplied to the light globe to make it light up.
4 Describe the energy transformations taking place in this circuit.
Optional
Students could also experiment with other substances in place of the
lemons such as vinegar, potatoes, cola or a cactus.
Voltmeter
Copper strip
Zinc strip
Copper strip
Zinc strip
Light globe
Conducting wire
lemon battery
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Megawatt Teacher Notes
Activity 6: Voltaic piles
What you need
• aluminium foil
• metal washers
• paper
• salt water
• other materials such as copper, zinc
• voltmeter
• wires.
What to do
1 Make a voltaic pile, (see diagram below) with paper dipped in salt water
sandwiched between aluminium foil and a washer.
2 Measure the voltage between the two metals with a voltmeter and record this value.
washer
paper
foil
Voltmeter
Conducting wire
3 Try multiple layers, (see diagram below) and record the voltage each time.
4 Try other combinations of metals, each time measuring and recording
the voltage with the voltmeter.
foil
foil
paper
paper
washer
washer
foil
Voltmeter
Conducting wire
paper
washer
Questions
1 State whether you constructed a single cell or a battery in each trial?
Explain your answer.
2 Which combination gave the greatest voltage reading?
3 Describe the energy transformations taking place in this circuit.
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Megawatt Teacher Notes
Activity 7: Battery life
What you need
• voltmeter
• wires
• light globe
• clock/watch
• several types of cells (for example, cheap and expensive carbon cells,
rechargeable Nicad cells, alkaline cells). They all need to be of the
same size, for example, D cells. Note the purchase price of each.
What to do
1 Set up the circuit shown in the diagram.
2 Take the voltage reading across the cell every two minutes and record
the results in a table.
3 As the cell goes flat and the light grows dimmer, note the voltage at
which you would consider the cell to be of little further use.
4 Mark this point on a voltage versus time graph for this cell.
5 Repeat for the other cells. If you wish for a shorter experiment, choose
smaller cells such as AA.
Questions
1 Which cell lasted longest?
2 Which one(s) died with very little warning?
3 For each cell, work out:
Time lasted (minutes)
cost (cents)
4 Which gave the best value for money?
voltmeter
1.5V D cell
Light globe
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Megawatt Teacher Notes
Electric circuits
Background information
Moving charge is called current. Conductors are materials that allow
current to flow easily through them. Metals for example are good
conductors of electricity. Insulators are materials that don't allow current
to flow through them easily. Examples of insulators are wood, glass and
plastic.
When an ammeter (instrument that measures current) is connected in a
circuit with a light globe and a good conductor, it will cause the light globe
to light up and the ammeter needle to move. Poor conductors will allow
electricity to pass through them and will make the ammeter needle move
but will not light the light globe. Insulators will not allow electricity to pass
through them so the light globe will not light up, nor will the ammeter
needle move.
When a battery or cell is connected in a circuit, it produces a current that
travels in one direction only. A current that flows in one direction only is
called direct current or DC current. The current that comes to your home is
called alternating current or AC current. This type of current is produced by
generators. AC current changes direction many times in one second. The
current that comes to your home alternates back and forth 50 times in one
second (50Hz). Some appliances have special electronic devices in them to
convert the AC current to DC current.
Electrical appliances convert electrical energy into other forms of energy
such as movement (kinetic), sound, light, heat (thermal) and stored energy
(potential energy). The energy in food and batteries is called chemical
potential energy. There are other types of potential energy. The energy of
compressed springs and drawn archery bows is mechanical potential
energy. Examples of objects that have gained gravitational potential energy
are lifts that are going up and boxes raised by forklift trucks.
Activities 8-17 relate to electric circuits.
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Megawatt Teacher Notes
Activity 8: Conductors and insulators
What you need
• Conductor worksheet (1 copy per group or individual, see page 22)
• 1.5 V battery
• small light globe
• four lengths of insulated wire
• a collection of objects such as a fork, copper wire, aluminium foil, plastic
object, dish of water, dish of salty water, graphite pencil (with both ends
sharpened), piece of wood, chalk, silver and gold rings and keys
• an ammeter (if available).
Primary teachers:
Many handy people may have a multi-meter which can act as an ammeter.
Alternatively, your local secondary school is likely to have an ammeter that
you can borrow.
What to do
1 Students construct an electrical circuit as shown in the diagram below.
2 Test the circuit by connecting a piece of wire between A and B.
The light globe should light up. Supply the groups with the objects
to be tested.
3 Allow the students to explore which objects act as good conductors
and light the light globe.
4 Students can then complete the Conductor worksheet that can be found
on the next page.
Questions
1 Which objects or substances caused the light globe to light up?
2 Are these materials good conductors or poor conductors?
3 Which objects or substances caused the needle on the ammeter to
move but not the light globe to light up?
4 Are these materials good conductors or poor conductors?
5 Which objects or substances didn’t affect the needle on the ammeter or
light up the light globe?
6 What are these materials called?
Material to be tested is
placed between A and B
1.5V cell
A
ammeter
B
Light globe
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Megawatt Teacher Notes
Made of?
Ammeter reading
(Amps)
Example:
Conducting wire
copper
1.4
Light globe
not lit
Light globe
dimly lit
Light globe
brightly lit
Conclusion
conducting wire is a good
conductor
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Conductor worksheet
Object tested
Megawatt Teacher Notes
Activity 9: Role-play a circuit
What you need
• a class of willing students
• a playground
• a bag of sweets.
What to do
This is a role-play activity which can be used to explain some of the potentially
confusing concepts involved in understanding electricity. It is designed for students of
all ages and the discussion can be extended or simplified to suit the understanding of
the students.
It should be emphasised to the students that in order for electricity or current to flow,
the circuit needs to have a continuous pathway (constructed with wires) for the
current to travel from the cell, through a load (light globe or electrical appliance) and
back into the cell.
This activity involves going outside and setting up a running track with several
obstacles. The obstacles could include benches to jump over, tyres to run through or
even playground bars to swing along. Explain the track to the students. Position the
students, one behind the other at the starting point of the track. Emphasise that they
are not to pass each other, and they must try to keep the line intact with no stragglers.
Tell them that they will get a sweet each time they pass you as you stand on the
track. Students must run around the track to obtain their sweet. Say go and let them
run around the track several times.
Classroom discussion
Parallels between the running track and electricity flowing in a circuit:
• the track represents the electric circuit
• the teacher on the track was the battery or energy source giving each student
new energy to run the circuit again
• the students are the charges running around the track
• the obstacles represent light globes or other appliances in a circuit
• the obstacles require a lot more energy to pass through or over than just running
on the track. The energy passing through anything is the voltage. Light globes
use a lot of voltage, wires require little voltage
• the sweets represent the current getting another boost of energy or voltage to
send them around again.
track = circuit
teacher on the track = battery or energy
source students = charges
energy = voltage
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Megawatt Teacher Notes
Optional
• a student can sit on the sidelines and count the number of students who pass in
a given time. The counting student represents the ammeter. The number of
students passing in a given time represents the current.
• add a short-circuit potential to your track by giving the students an option of
missing one of the obstacles. Observe their choices and discuss what happens in
a real circuit with most of the energy taking the easiest (least energy intensive)
route, but with some still choosing to complete the obstacle course.
• senior students could discuss its effectiveness as a model to describe electricity
in a circuit. Some questions that could be included are listed below.
Questions
1 How close are the definitions provided by the model to the actual definitions
of current, voltage and charge?
2 When a high resistance load is short-circuited, some charge still flows through
the high resistance load. How effective is the model at explaining this?
3 Why does this model not satisfactorily explain how the voltage (energy source) is
used by the current as it moves around the wires in the circuit?
Cell/battery
charges
Load/resistor
Load/resistor
Load/resistor
Pathway = conducting wire
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Megawatt Teacher Notes
Activity 10: Switches and circuits
What you need
• cell (battery)
• tape
• three pieces of insulated wire
• light globe
• two drawing pins
• small piece of cork
• paper clip.
What to do
Ask the students to:
1 Try to use one cell and one wire to make the light globe light up. Is this possible?
2 Use one light globe, one cell and two wires and make the light globe light up.
3 Make a switch as seen in the diagram below. Tape one wire to the base of the
cell and attach it to the light globe.
4 Fix the third wire to the top of the cell with tape, and to the light globe as well. By
pressing the paper clip down, the circuit will be complete and the light globe will
light up.
Paper clip
cell
switch
Light globe
Questions
1 Were you able to light up the light globe using only one cell and one wire? Try
to explain why.
2 Describe the energy transformations that took place in the circuit you constructed
in part 2.
3 Why do you think switches are useful in electric circuits?
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Megawatt Teacher Notes
Activity 11: Appliance science
What you need
• a copy of the Appliance worksheet per student (page 28).
What to do
On the Appliance worksheet, students fill in the household electrical appliance name,
its use and the forms of energy produced, as shown by the example.
Questions
1. Which ones are the most efficient, and produce only the energy we want or need?
2. Which information are you basing your answer on?
3. Which of these devices could you easily live without?
4. Were these devices available fifty years ago? If not, what was used as the
alternative? For example you might consider a hand whisk instead of an
electric beater.
5. Cut out pictures of appliances from various catalogues and glue them onto an
A3 sheet and create a collage illustrating the appliances that produce particular
types of energy.
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Megawatt Teacher Notes
Appliance worksheet
Name of appliance
Energy we want
Other forms of
energy produced
Alternative (before
electricity)
Example: Light globe
Light
Heat, some sound
candle
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Megawatt Teacher Notes
Activity 12: Electric jug
What you need
• paper
• pencils
• electric jugs (old and new ones if possible).
What to do
1 Ask the students to imagine and then draw an electric jug.
2 Ask them to label its parts and to list the materials it is made from.
3 Display some electric jugs for them to compare to their drawing.
4 Discuss the various parts and materials used in each jug and how their
construction relates to the age of the jug.
5 Examine an electric jug by pulling one apart.
6 Discuss the various parts and materials further.
7 What energy transformations are taking place in this appliance?
Activity 13: Invent an appliance
What you need
• advertising brochures containing pictures of electrical appliances.
What to do
1. Discuss with students the fact that there are new appliances coming onto the
market all the time (especially at Christmas). Some of these may be considered
to be less useful than others, (for example, an electric nose hair clipper).
2. Look in catalogues or science magazines to discover any appliances that may
fall into this category.
3. Design an electrical appliance. Consider what its power source is, how much it
will cost and who it is designed for.
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Megawatt Teacher Notes
Activity 14: Electrical safety
What you need
• research facilities
• poster paper
• graph paper
• volunteers
• multiple copies of the Electrical safety worksheet.
What to do
Ask the students to:
1 Answer the questions on the Electrical safety worksheet to find out how much
they know about electrical safety.
2 Do some research on electrical safety and investigate common misconceptions
about electrical safety.
3 Make a poster demonstrating the DOs and DON’Ts when using electrical appliances.
Optional
Ask the students to:
4 Survey ten people they know using the Electrical safety worksheet and graph
the findings.
5 Survey classmates or other year levels using the Electrical safety worksheet
to compare different age groups.
6 Compare the results of boys against girls in a graph.
Answers to the quiz
1F
2T
3T
4T
5F
6T
7F
8T
9T
10F
11F
12T
13T
14F
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Megawatt Teacher Notes
Electrical safety worksheet
Are you switched onto electrical safety?
Read each statement carefully and decide if it is true or false.
Write
T
or
F
in each box.
1
Any tradesperson listed in the telephone book is qualified
to do electrical work in your home.
2
If you are outside playing in a thunderstorm the best thing
to do is to go indoors.
3
Using double adaptors increases the risk of overheating
and fire.
4
You should not use the telephone during a thunderstorm if
it has a cord to the wall.
5
All houses in Victoria have a safety switch in their
switchboard.
6
You should always wear shoes when you use the washing
machine.
7
It is safe to fly a kite near power lines.
8
The human body can conduct electricity.
9
If a power line is broken and has fallen down you should
stay at least six metres away.
10
When working outside with electrical appliances you should
wear thongs.
11
If an electric cord is frayed, the best thing to do is wrap
electrical tape around it.
12
All electrical appliances should be switched off and
unplugged when not in use.
13
If an appliance is faulty you should have it fixed or destroy
it.
14
Babies are too small to get hurt if they poke things into a
power point.
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Megawatt Teacher Notes
Activity 15: Check your electricity use
What you need
• paid electricity bills.
What to do
Electricity bills are presented with bar graphs comparing our monthly consumption.
Ask the students:
1 To bring in a paid bill and in groups think of reasons why the electricity
usage fluctuates.
2 Brainstorm ways to save on electricity bills.
3 Think about and record how they can put these suggestions into practice.
4 Find out whether the appliances at home have a star rating. Find out what the
energy star rating represents.
Activity 16: Electrical safety at home
What you need
• research facilities.
What to do
Ask your students to use the research facilities available to complete the
following questions.
Questions
1 Draw circuit diagrams to help explain why and how metal appliances are earthed.
2 How do safety switches (earth leakage circuit breakers) work?
3 Why aren’t normal fuses adequate?
4 How does a danger still exist even when safety switches are being used?
5 What is the International Colour Code for electrical wiring and why did
Australia change over from the old code?
6 What is the lethal dosage of current for the human body?
7 How should you approach and treat anyone who suffers a large electric shock from
(a) a domestic 240V source and
(b) a high voltage source?
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Megawatt Teacher Notes
Activity 17: Life without electricity
What you need
• elderly relatives or friends or
• research facilities.
What to do
Ask the students to:
1 Predict the effect of the loss of electricity on their lives.
2 Discuss with an elderly adult what they used instead of selected electrical
appliances (for example, a hand whisk instead of an electric beater, or a copper
and a mangle instead of a washing machine).
The students can also research this using the library.
Results can be presented as:
• an oral presentation to the class
• inviting a grandparent to visit the school to discuss the questions the students
may have
• a video recording of an interview between the elderly person and the student
• a creative story describing the experiences of the elderly person
• a role-play demonstrating the hardships experienced when completing a task that
is now made easier by an advanced electrical appliance.
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Megawatt Teacher Notes
Electromagnets and electric motors
Background information
Hans Christian Oersted discovered that electric currents produce magnetic fields. He
noticed that a magnetic compass needle moved when it was placed near a wire
carrying current. This suggested that current carrying wire had a magnetic field just
like ordinary magnets. When the current is switched off, the wire stops being a
magnet. Magnets that you are familiar with are generally magnetic all the time. By
winding wire around particular metals and passing a current through the wire, we can
make a stronger electromagnet. Big electromagnets are used to move scrap iron junk
in car yards from one pile to another by switching the electromagnet on to pick up the
metal scrap and off to drop it.
The power supply in Australia brings AC current to every household. The frequency
of the household power supply in Australia is 50 Hertz. This means that the current
goes forwards and backwards 50 times each second. If you brought a magnet close
to an incandescent light globe which was switched on, the filament would vibrate. The
filament vibrates because the magnetic field around the magnet and the magnetic
field produced by the current carrying wire are interacting causing a force to be
exerted on the filament. The direction of the force will depend on the direction of the
current. Since the current is moving back and forth many times a second, the filament
is seen to vibrate.
The discovery of electromagnetism led to the discovery of the principle behind
the electric motor by Michael Faraday. Michael Faraday discovered that when a
current carrying wire is placed between magnets, the wire experiences a force.
When a coil of current carrying wire is placed between magnets, the coil turns. This
is the basis of a simple electric motor. The speed of the rotating motor can be
increased by increasing the number of coils between the magnets, increasing the
current in the wire or by using stronger magnets.
Activities 18-22 relate to electromagnets and electric motors.
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Megawatt Teacher Notes
Activity 18: A simple electromagnet
What you need
• Electromagnet worksheet (1 per student or group, see page 35)
• large nail or bolt
• long piece of insulated wire
• 1.5V cells (batteries)
• a packet of paper clips.
What to do
Ask the students to:
1 Strip the insulation from each end of the wire and twist the strands together.
2 Wind the wire around the nail about 15 times.
3 Connect the two ends of the wire to opposite ends of the cell.
4 Hold the nail close to a small pile of paper clips.
5 Count how many paper clips were picked up and record the number in the table
on the Electromagnet worksheet.
6 Repeat steps 2-5 changing the number of coils of wire wrapped around the
nail, each time recording the number of paper clips picked up by the electromagnet.
7 Try connecting two cells in the circuit and repeat steps 2-6.
Questions
Refer to the findings on the Electromagnet worksheet.
1 How many paper clips can be picked up using 15 coils and one cell?
2 How many paper clips were picked up using 25 coils and two cells?
3 Did connecting more cells in the circuit affect the number of paper clips
picked up?
4 What affects the number of paper clips that can be picked up?
Optional
Encourage the students to experiment with various combinations of the number of
cells and the number of coils.
cell
wire
nail
Paper clip
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Megawatt Teacher Notes
Electromagnet worksheet
Fill in the number of paper clips lifted in each column
Number of winds of wire
15
Number of cells
20
25
30
1
2
cell
wire
nail
Paper clip
Use the results in the table above to answer the following questions.
Questions
1 How many paper clips can be picked up using 15 coils and one cell?
2 How many paper clips were picked up using 25 coils and two cells?
3 Did connecting more cells in the circuit affect the number of
paper clips picked up?
4 What affects the number of paper clips that can be picked up?
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Megawatt Teacher Notes
Activity 19: An electromagnet with a switch
What you need
• large nail or bolt
• long piece of insulated wire
• smaller piece of wire
• 1.5V cell (battery)
• a packet of paper clips
• two drawing pins
• small cork.
What to do
Ask the students to:
1 Make a switch using the drawing pins, the cork and a paper clip.
2 Press one drawing pin into the side of the cork so that it anchors the single end of
a paper clip.
3 Push the other drawing pin into the other end of the same side of the cork.
4 Swivel the paper clip so it is able to touch the other drawing pin. This closes
the switch.
5 Wind the long piece of wire around the nail 15 times.
6 Connect one end of each wire to one end of the cell and the other end to one of
the drawing pins.
7 Connect the second wire to the other end of the cell and the other drawing pin.
When the switch is closed (touching the drawing pin) the electromagnet should be
able to pick up paper clips. When the switch is open it is no longer magnetic.
switch
cell
cork
nail
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Megawatt Teacher Notes
Activity 20: Dancing dolly
What you need
• thick steel bolt
• insulated wire
• stiff paper
• scissors
• pencils
• paper clips
• small cardboard box (about the size of an individual fruit drink box is suitable)
• two cells (batteries)
• tape
• switch from Activity 19
• rubber band
• wire coat hanger.
What to do
Ask your students to:
1 Wind the wire around the bolt about 100 times.
2 Connect to the switch and the cell as in the previous activity, but use two cells
taped together. (See diagram below.)
3 Place the cardboard box over the electromagnet making sure the magnet is close
to the top of the box.
4 Draw and cut out a doll body from stiff paper. Use two paper clips for each arm
and each leg of the doll.
5 Connect wire from the coat hanger to the box with tape and twist the free end so
that the doll can hang just above the box with the aid of a rubber band.
6 Press and release the paper clip switch and the doll will dance.
Coat hanger wire
Cells/battery
switch
electromagnet
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Megawatt Teacher Notes
Activity 21: Vibrating light globes
What you need
• strong magnet
• clear 240V household incandescent light globe connected to the mains power supply
(for example, a table lamp with the shade removed). Use a low wattage light globe
to avoid eye damage.
What to do
Ask students to:
1 Bring the magnet near a light globe that is not switched on and record observations.
2 Now bring the magnet near the light globe when it is switched on and
record observations.
Questions
1 Is the filament a magnetic material? Explain.
2 Why do you think the filament vibrated?
3 Your observations are based on what happens when you put a magnet near a
filament using AC current. What do you think the filament would do if the
current through it only moved in one direction (using DC current)?
It is very important that magnets should not be brought close to computer screens
or televisions as this can permanently affect the screen image.
Filament vibrates back and forth
Lit light
globe
magnet
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Megawatt Teacher Notes
Activity 22: Simple electric motors
What you need
• lacquer-coated copper wire (about 80cm)
• large paper clips
• small box or cylinder
• rubber bands
• wire
• 6V DC power supply or a 6V battery
• strong bar magnet
• sharp knife or razor blade
• a plastic film canister.
What to do
Ask students to:
1 Make a coil from copper wire by winding it around a suitable cylinder.
Scrape lacquer coating
off this top side only
Scrape lacquer coating
off this top side only
coil
2 Set equipment up as in the diagram below, with the power supply set to 6V DC or using a 6V
battery.
coil
Cylinder or box
magnet
Rubber bands holding
paper clips in place
Conducting wires
6V DC power supply
3 Spin the loop by hand. With the magnet in the right position (found by trial and error)
the loop will continue to spin.
Questions
1 What is the basic principle behind the electric motor?
2 Who was the person credited with making the first electric motor?
3 Find out what changes you can make to your model to make the motor spin faster.
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Megawatt Teacher Notes
Generators
Background information
Michael Faraday was the first person to make an electric generator. He understood that
many electrical effects are reversible. A simple electric generator is just a simple electric
motor in reverse. Generators convert movement into electricity. A motor requires
electricity to turn coils of wire between magnets and a generator produces electricity
when coils of wire are turned between magnets.
Power stations have huge turbines that are used to turn a huge number of coils between
magnets to produce electricity that eventually reaches your home. There are different
types of power stations. There are those that turn turbines using steam from burning
coal. Others use nuclear energy. Some are more environmentally friendly and use wind
or water.
Activities 23-24 relate to generators.
electricity
Flue gas
Cooling tower
generator
turbine
steam
boiler
water
coal
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Megawatt Teacher Notes
Activity 23: Do-it-yourself generator
What you need
• solenoid (wire coil)
• iron bars to place in the solenoid (the uprights can be unscrewed from retort stands),
• bar magnets
• wires
• galvanometer.
What to do
Ask students to:
1 Connect the solenoid to the galvanometer.
2 Move the north end of the magnet in and out of the solenoid (more than once)
and record their observations.
3 Move the south end of the magnet in and out of the solenoid (more than once)
and record their observations.
4 Move the magnet back and forth around the solenoid and record their observations.
5 Insert an iron bar inside the solenoid and see what effect this has on the
current reading. Record their observations.
6 If you can alter the number of coils in the solenoid, increase the number of coils.
7 Repeat steps 1 - 5 and record the differences observed.
Questions
1 Was a current registered on the galvanometer when the magnet was not moving?
2 Did the direction or reading of the current change when the magnet was inserted
and then removed? Explain.
3 Did the speed of the magnet’s movement affect the current?
4 Was there a difference in the current reading or direction when the magnet
was inserted the other way around (with the south end entering the solenoid
first)?
5 Does placing an iron bar in the coil have any effect?
6 Does increasing the number of coils affect the direction of the current or the
current reading on the galvanometer?
Solenoid
Moving magnet
Galvanometer
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Megawatt Teacher Notes
Activity 24: Power to the people
What you need
• recording materials.
What to do
Brainstorm with students where they think mains electricity comes from. This activity
will allow you to assess their level of understanding.
Classroom discussion points
• in coal-powered power stations the generators convert the energy of brown coal
into electrical energy
• it is easier to transport electricity rather than brown coal, thus the power station
is close to the coal supply
• is electricity a clean source of power? Consider living next to the power station
• about half the energy from brown coal is lost as heat. One quarter is used to
dry the brown coal itself. One quarter is turned into electrical energy
•
the energy from brown coal is used to turn a generator. What other forms of
energy can be used to turn a generator? Which alternative forms of electricity
production do not use an electrical generator?
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Megawatt Teacher Notes
Sustainable energy
Background information











Energy is the ability of something to do work.
Energy cannot be created nor destroyed, but can be transformed from one
form to another.
Kinetic energy is due to an object's movement (from the Greek word
Kinema, from which we also get the word cinema).
Gravitational potential energy is due to the height of an object above some
surface. Heat is due to the movement or vibration of particles (atoms or
molecules). The higher the temperature of an object, the faster the particles
move or vibrate.
Light is a form of radiant energy.
Electrical energy is due to the movement of electricity.
Chemical energy is due to the chemical reactions that can occur in the object.
You contain chemical energy because of the food you ate, you can transform it
to kinetic, potential, sound and heat when you walk up stairs. Batteries contain
chemical energy and transform it to electrical energy.
Work is done when energy is transformed from one form to another, or a force
moves something through a distance.
Solar energy is light energy that comes from the Sun. It is usually transformed
into heat. It can be transformed into electricity using photovoltaic (PV) cells.
Photovoltaic cells are often called solar cells. Plants convert solar energy into
stored chemical energy by the process of photosynthesis.
Wind energy is the energy of moving air, so it is an example of kinetic energy. It
can be transformed into electrical energy using a turbine to drive a generator.
Water has kinetic energy when it is moving. It too can be transformed into
electrical energy using a turbine to drive a generator.
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Megawatt Teacher Notes
Activity 25: Photovoltaic cell
What you need
• Solar (photovoltaic) cell
• Connecting wires and clips
• Small DC motor
• Fan
What to do
1
Connect the fan blades to the motor shaft.
2
Connect the motor to the solar cell module.
3
Place the solar cell module flat on the ground in direct sunlight.
4
Observe what happens when you alter the angle that the solar module makes
with the sunlight.
5
Slowly slide a piece of thick card across the solar module to cover it. Observe
the effects on the speed of the fan.
Questions
1
Describe what happens when the solar module is placed in direct sunlight.
2
Describe the effects of changing the angle of the solar module.
3
How much of the solar module was covered before the fan stopped rotating?
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Megawatt Teacher Notes
Wind or water turbines
A turbine is a prime mover that usually consists of a wheel with a number of curved
vanes attached. Wind or water pushes the vanes and makes the wheel rotate. The
turbine is connected to a generator to produce electricity. A pinwheel is an example
of a turbine.
Activity 26: Make a pinwheel
What you need
• Thin cardboard (for example, manilla folder)
• Ruler
• Pencil
• Scissors
• Pin
• Eraser-tipped pencil
• Photocopy of the pinwheel template (see page 47)
What to do
1 Glue the template onto the cardboard and cut out.
2
Cut along the diagonal broken lines.
3
Make five small holes where indicated, then bend the cardboard to line up the holes.
4
Push the pin through the five holes, then push the sharp end into the eraser.
5
Hold the pinwheel near a fan. Change the speed of the fan and try to count the
number of times the pinwheel spins around every 10 seconds, at different fan
speeds.
Questions
1
What energy transformations are happening?
2
How many times did the pin wheel spin when the fan was on the following settings?
Low
Medium
High
3
How can water be used to turn the pinwheel?
4
Describe a way of using a pinwheel to make electricity.
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46
Megawatt Teacher Notes
Pinwheel template
http://museumvictoria.com.au/scienceworks/education/education-programs/megawatt-/
47
Megawatt Teacher Notes
Activity 27: Electricity time-line
What you need
• brief biographies of the famous people associated with electricity found
on pages 49-51.
• research facilities and/or other resources.
What to do
Ask students to:
1 Construct a ‘developments in electricity’ time-line using the relevant
information outlined on pages 49-51.
2 Choose one of the following people to research in more detail and write a
report about them:
•
•
•
•
•
•
Thomas Edison
Nikola Tesla
Alessandro Volta
Michael Faraday
Benjamin Franklin
Hertha Ayrton.
Optional questions
1 When did they live?
2 What was/were their main contribution(s) to our knowledge of electricity?
3 Were any units named after them?
4 Describe what life was like in their day and the effect that their discovery had
on people’s day to day lives.
Present the report in poster form for display in the classroom, or other form as
agreed with your teacher.
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48
Megawatt Teacher Notes
Biographies
Namarrkon
The Aborigines of northern Australia have a number of stories that explain thunder,
lightning and the wet-season clouds and rain. Namarrkon (spelling varies as the
consonant sounds have no exact equivalent in English) is the Lightning Spirit of the
Kunwinjku people of Western Arnhem Land in the Northern Territory. He/she has a
circle of lightning leading from his/her head to the lower parts of his/her body
representing flashing lightning. Namarrkon creates electrical storms and destroys
trees by throwing the stone axes that protrude from his/her knees and elbows. It is
widely believed that the marrkidjbu or ‘clever men’ have the power to call on
Namarrkon to strike a particular person whom they wish to have killed.
Thor
Thor was the God of Thunder in Norse (Northern European) mythology. He had a
magic hammer which he threw with the aid of iron gloves. It always returned to him.
Lightning strikes occurred when his hammer hit something hard. Thunder was the
sound of his rolling chariot. Thor was the eldest son of Odin, the ruler of all gods.
Thursday is named after Thor.
Thales (about 580 B.C.)
Thales found that a piece of amber (fossilised plant sap), when rubbed with a cloth,
attracted feathers and the dried pith of plants. Thales was born in Miletus in Asia
Minor. He is considered to be the founder of Greek philosophy and was one of the so
called Seven Sages (Wise Men) of Greece. He explained many natural phenomena.
The Greek word for amber is elektron (hlektron).
William Gilbert (1544–1603)
William Gilbert determined that a compass needle points north because the Earth
behaves as a giant magnet. In 1600 he published a book, De Magnete, which gave
a full account of all his experiments on magnets and electrical attractions. His book
was used as the ‘bible’ of electricity and magnetism for over 150 years. William
Gilbert was an English physicist and physician who was educated at the University
of Cambridge. He was appointed physician to Queen Elizabeth I.
Benjamin Franklin (1706–1790)
Benjamin Franklin performed his famous experiment with a kite in 1752. He flew a kite
in a thunder storm. The kite was used to ‘capture’ lightning, using a special storage
device called a Leyden Jar. The Jar was connected to the kite by a string. His
experiments were the first to show that lightning is electricity. He was very lucky not to
have been killed! Others have not been so fortunate. He also explained how objects
became charged and discharged using his theory of ‘positive’ and ‘negative’ charge.
Benjamin Franklin was an American printer, author, diplomat and philosopher as well
as a scientist.
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Megawatt Teacher Notes
Petrus van Musschenbroek (1692–1761)
The Dutch physicist, van Musschenbroek is one of the two people credited with
the invention of the Leyden Jar which was used to store static electricity. His Jar
was a water-filled glass jar with an iron rod in it. The Leyden Jar was discovered
in about 1745 by two scientists who were working independently. The other
scientist was Ewald George von Kleist. The Leyden Jar was named in honour of
the city of Leyden, where van Musschenbroek was born.
Ewald George von Kleist (1700–1748)
Ewald George von Kleist discovered the Leyden Jar independently of van
Musschenbroek. His model used a chain in a glass jar, quite different to van
Musschenbroek’s, which used an iron rod. Ewald George von Kleist was the Dean of
the Kamin Cathedral in Pomerania (now a part of Poland).
Otto von Guericke (1602–1686)
Otto von Guericke developed the first machine for producing an electrical charge. It
consisted of a sulfur ball which could be spun on an axle. The turning ball would be
brushed with a hand, a soft leather pad or a wool cloth. Its operation was
accompanied by showers of sparks. Otto von Guericke was a German physicist who
studied law and mathematics. He also did many experiments on air pressure,
including the famous Magdeburg hemispheres demonstration, and invented the first
air pump.
Luigi Galvani (1737–1798)
Luigi Galvani accidentally discovered that he could make a frog’s leg twitch violently
when it was touched in different places by iron and copper rods. He (wrongly) thought
that the frogs leg contained ‘animal electricity’ that was released when it was touched
by these metals. It was Volta who proved that the frog’s leg and the two different
metals were behaving like a battery. Luigi Galvani was an Italian professor of
anatomy. The electrical terms, GALVANISM and GALVANISATION, were named in his
honour.
Allesandro Volta (1745–1827)
Alessandro Volta developed the first battery, called a Voltaic Pile. It consisted of
stacked copper and zinc plates, separated by paper or cloth that had been soaked in
salt water. Voltaic piles were the first steady source of electric current. He was an
Italian physicist who performed many experiments with electricity. In honour of his
work, Napoleon made him a Count, and the electrical unit the VOLT was named after
him.
Hans Christian Oersted (1777–1851)
In 1818, Hans Christian Oersted discovered that a magnetic compass needle will
move when it is placed near a wire carrying a current. He also discovered the first
electromagnet. This discovery began the study of electromagnetism, an important
step in the path to the first electric motor. Hans Christian Oersted was a Danish
physicist who was educated at the University of Copenhagen. He was the first
person to extract the metal aluminium. The magnetic unit, the OERSTED, is named
in his honour.
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Megawatt Teacher Notes
André Ampère (1775–1836)
André Ampère built the first meter for measuring electricity. He was the first person to
work out the mathematical relationship between electricity and magnetism. He was a
child prodigy who mastered every aspect of mathematics by the time he was twelve.
He went on to become a professor of physics, chemistry and mathematics at different
universities in France. The unit of measurement of electric current, the AMPERE, is
named in his honour.
Michael Faraday (1791–1867)
In 1821, Michael Faraday discovered the principle of the electric motor. A motor
converts electricity into movement. He understood that many electrical effects are
reversible. For example, he was the first person to make an electrical generator, which
converts movement into electricity. Michael Faraday was the son of an English
blacksmith and he received little formal education. He became a physicist and
chemist, best known for his discoveries of electromagnetic induction and electrolysis.
The electrical unit, the FARAD, was named in his honour.
Thomas Edison (1847–1931)
Thomas Edison developed the electric light bulb, the electric generator, the
phonograph and the motion picture. Altogether, Edison patented more than 1000
inventions. In 1882, he developed and installed the world’s first large central electric
power station in New York city. The generator supplied direct current. Later generators
produced alternating current, as proposed by Nikola Tesla and George Westinghouse.
Nikola Tesla (1856–1943)
In 1888, Nikola Tesla developed the first system for generating alternating current.
George Westinghouse installed this system in the Niagara Falls power station, which
opened in 1895. In 1891, Tesla developed a high voltage transformer–the Tesla coil–
which has important applications in the field of radio communications. He was an
electrical engineer and inventor who was born in Smiljan (in the former Yugoslavia)
and emigrated to the United States in 1884. He later became an American citizen.
The magnetic unit, the TESLA, is named in his honour.
Hertha Ayrton (1854–1923)
Hertha Ayrton worked on the development of electric arc lamps. Her inventions
were used as searchlights during World War I and in the cinema. Hertha Ayrton was
born in England. She was trained as a mathematics teacher, but went on to
become an electrical engineer. She published many papers on electric lighting. She
was the first woman to become a full member of the Institution of Electrical
Engineers. She was refused membership of the Royal Society on the grounds that
she was a married woman.
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Megawatt Teacher Notes
Resources
Internet addresses
Power stations and generation
Information about power stations in
Victoria http://www.loyyangpower.com.au
The Australian Renewable Energy web site:
http://www.agso.gov.au/renewable/
Understanding electricity
More activities to do with electricity and sustainable energy resources suitable for Years
1- 10:
http://www.originenergy.com.au/about/about_subnav.php?pageid=565#
Lightning photography
http://www.photopixels.com/lightning/index.html
Fundamentals of electricity
http://www.epelectric.com
Understanding static electricity
Detailed information about static electricity as well as some fun experiments to
try. http://www.sciencemadesimple.com/static.html
Victorian Model Solar Vehicle Challenge
http://www.modelsolar.org.au
Power for a Sustainable Future
This highly recommended site contains fact sheets, student activities, teacher
resources and a glossary
http://www.sustainableenergy.eq.edu.au/sources/index.html
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Megawatt Teacher Notes
Excursion ideas
PowerWorks Museum Exhibition Centre
PowerWorks provides educational tours for primary and secondary students
in science and environmental studies.
Contact:
PowerWorks
Ridge Road
MORWELL, 3840
Ph: (03) 5135 3415 http:/www.powerworks.com.au/
The Energymobile or The Solar Shuttle
Travelling interactive display on solar, water, wind and human energy.
A range of educational programs for primary, secondary and VCE students are
available.
Contact:
Alternative Technology Association
ATA Head Office
2nd Floor, 332 Albert St
East Melbourne VIC 3002
Phone: (03) 9419 2440
Fax: (03) 9419 2441
Email: ata@ata.org.au http://www.ata.org.au/
CERES (Centre for Education and Research in Environmental Strategies)
The centre for energy studies provides access to a variety of hands-on activities and
demonstrations in energy use, alternative technologies, energy efficient building
design and smart energy solutions. Programs cater for primary, secondary, VCE and
tertiary groups.
Contact:
CERES
8 Lee St
BRUNSWICK, 3056
Ph: (03) 9387 2609
http:/www.ceres.org.au/
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53
At the ORANGE lit panel copy
the heading in the space below.
Visit activities
This model shows that wind
energy can be converted into
electrical energy.
Find the exhibit Solar panel.
Follow the directions.
• What happens to the fan when
you press the yellow button?
• Tick the correct answer(s).
This electrical energy is then
converted into:
heat energy
light energy
sound energy
movement energy
Activity set A for Years 3 - 5
There are seven different
coloured stations in the Megawatt
exhibition. You or your group can
choose which one to start at.
At the WHITE lit panel copy the
heading in the space below.
Tick the correct answer(s):
• The Carpet Static exhibit shows
that movement energy is being
converted into:
heat energy light
energy electrical
energy sound
energy
At the BLUE lit panel copy the
heading in the space below.
This model shows that solar
energy can be converted into
electrical energy.
• Tick the correct answer(s).
This electrical energy is then
converted into:
heat energy
light energy
sound energy
movement energy
Find the exhibit Wind farm.
Follow the directions.
• How many houses were you
able to light up?
Find the exhibit Micro-hydro.
Follow the directions.
Find the exhibit Fishy fibres.
• Describe what is happening?
• Which person has caught the
blue fish?
• Find and write down two
animals that can detect
electricity.
This model shows that the
energy of falling water can be
converted into electrical energy.
• Tick the correct answer(s).
This electrical energy is then
converted into:
heat energy
light energy
sound energy
movement energy
1.
2.
Find the exhibit: Carpet static.
Follow the directions to make
electricity.
• What two items are being
rubbed together?
1.
2.
Number
Find the exhibit Morse code to
the rescue? Follow the directions.
• Use the code below to write
down your initials in Morse
code.
Morse code:
A._
B_...
C_._.
D_..
E .
F.._.
G__.
H....
I..
J .___
K _._
L ._..
M __
N _.
O ___
P .__.
Q __._
R ._.
S ...
T _
U .._
V ..._
W.__
X_.._
Y_.__
Z__..
Tap out your initials in morse
code.
57
54
At the RED lit panel copy the
heading in the space below.
• Hold the red magnet still
inside the coil of wire.
• Which combination of metals
(a, b or c) did the needle bend
the most?
Describe what happens to the
needle now.
Touch the metal plates at the
same time.
At the YELLOW lit panel
copy the heading in the space
below.
Look at the possum in the glass
case. Read the label with the
heading ‘Precarious possum’ (2).
Find the exhibit How a speaker
works. Follow the directions.
• Tick the correct answer(s).
Find the exhibit Hand battery.
Follow the instructrions shown on
the diagrams below.
• Draw where the needle
reaches on each diagram.
Find the exhibit Magnet and coil.
A moving needle on the dial
shows us that electricity has been
made.
Join hands with a friend.
Use the free hand on both ends
to touch the metal plates.
• Describe what happens.
Movement energy is
converted into:
light energy
sound energy
heat energy
At the PURPLE lit panel copy
the heading in the space below.
(a)
Try with more than one friend.
Find the exhibit DC Motor.
Follow the directions.
Zinc
Zinc
Pressing the yellow button
supplies electricity to the motor.
Voltage
Move the red magnet through the
coil of wire.
Copper Aluminium
•
Aluminium Copper
Find the fire ant in the glass case.
(b)
Zinc
Zinc
What happens when you wind
the magnets closer to the coils
of wire?
• What dangerous thing is the fire
ant doing?
Voltage
the needle does not move
the needle moves a little
the needle moves a lot
• Describe what happens.
At the GREEN lit panel copy the
heading in the space below.
• What will happen to the
possum if it touches the other
wire?
• Tick the phrase which best
describes the needle on the
meter.
Find the exhibit Completing the
circuit.
Copper Aluminium Aluminium Copper
(c)
Zinc
Zinc
Voltage
Copper Aluminium Aluminium Copper
55
56
Visit activities
Find the exhibit Switch logic.
Set up the two different circuits as illustrated on the display panel.
Watch what happens to the light globe in each case when you close the switch.
• What is necessary for electricity to flow in an electric circuit?
_________________________________________________________
Activity set B for Years 5 – 8
Find the exhibit Parallel and series circuits.
Set up two light globes in series and two light globes in parallel as shown in the diagrams below.
There are seven different coloured stations in the Megawatt exhibition. You or your group can
choose which one to start at.
Read the WHITE lit panel titled ‘Electricity is everywhere, in everything!’
Series circuit
Parallel circuit
•
In what parts of the body can electricity be found?
_________________________________________________________
Find the fire ant in the glass case. Read the label inside the
glass case to find out why fire ants can be found throughout
this exhibition.
• How do you think fire ants obtained their name?
__________________________________________________________________________
•
Read about the strange looking shark in the
glass case.
• What type of shark is it and why is the head shaped like it is?
What happens when you remove one light globe from the series circuit?
_____________________________________________________________________
• What happens when you remove one light globe from the parallel circuit?
__________________________________________________________________________
__________________________________________________________________
__________________________________________________________________________
Read the BLUE lit panel titled ‘Electricity - for communication!’
Find the exhibit Completing the circuit.
Touch the metal plates at the same time.
• Describe what happens.____________________________________________
How fast do electrical signals travel?
kilometres per second
Join hands with a friend. Use the free hand on both ends to touch the metal plates.
• Describe what happens. ____________________________________________
Try it with more than one friend.
•
Travelling at these speeds, why do we still experience delays in communication?
___________________________________________________________________________
Read the ORANGE lit panel titled ‘Electricity - sustainable energy!’.
___________________________________________________________________________

•
What are some other ways of making electricity other than by burning fossil fuels?
_____________________________________________________________________
Find the exhibit Solar panel.
________________________________________________________________________
Follow the directions.
• What type of energy is being converted to electrical energy?
_____________________________________________________________________
Find the exhibits Micro-hydro and Wind farm. Follow the directions on both these exhibits.
•
Look for the different types of cables in the glass case. Name two
differences between a co-axial cable and an optical fibre cable?
________________________________________________________________________
What type of energy is converted to electrical energy on the wind farm?
_____________________________________________________________________
•
What type of energy is converted to electrical energy in the Micro-hydro?
_____________________________________________________________________
61
58
Read the GREEN lit panel titled ‘Electricity takes us places!’.
Find the exhibit Morse code to the rescue?
Follow the directions.
• Use the code below to write down your initials in Morse code.
•
Name some vehicles that use electricity to take us places
________________________________________________________
_________________________________________________________________________________________
Morse code:
Find the exhibit Hand battery.
Put your left hand on the zinc plate and your right hand on the copper plate.
• Write down the meter reading. _____________________________________________________________
A._
B_...
C_._.
D_..
E .
F.._.
G__.
H....
I..
J
K
L
M
N
O
P
Q
R
.___
_._
._..
__
_.
___
.__.
__._
._.
S ...
T _
U .._
V ..._
W.__
X_.. _
Y _ ._ _
Z __. .
•
What happens when you try two metals that are the same?
_________________________________________________________________________________________
Find the exhibit Wet cell.
Lower the zinc plate on the left hand side and the copper plate on the right hand side into the
liquid.
• Write down the meter reading _____________________________________________________________
•
You have tried copper and zinc for both the Wet cell and the Hand battery. Are the readings different? Why?
_________________________________________________________________________________________
Read the RED lit panel titled ‘ Electricity - a controlled energy supply!’
•
_________________________________________________________________________________________
Read the YELLOW label titled ’Electricity entertains us!’
What are our main sources of energy for the generation of electricity in power stations?
___________________________________________________________________________________
___________________________________________________________________________________
•
•
What are some of the things we would have had to do without if we had no electricity?
_______________________________________________________________________________________
Look at the sparrow and the possum inside the glass case. Read the labels and find out
why the sparrow will not get electrocuted sitting on the power line but the possum may be in
trouble.
Find the exhibit How a speaker works. Follow the
______________________________________________________________________________________
•
directions.
Cross out the incorrect word in the following statements.
______________________________________________________________________________________
(a) Faster/Slower vibrations make higher notes.
(b) Faster/Slower vibrations make lower notes.
Find the exhibit Circles of magnetism.
Look at the compass needles, then press the yellow button.
• What do you notice?
Read the PURPLE lit panel titled ‘Electricity - safety at home!’.
________________________________________________________________________________________________
•
Find the exhibit Magnet and coil.
Move the red magnet through the coil of wire.
• What is the effect on the meter?
1.
_________________________________________________________________________________________
What two conditions make electric circuits in the home safe?
_________________________________________________________________________________________________
2.
_________________________________________________________________________________________
Hold the red magnet still inside the coil of wire.
• What is the effect on the meter?
__________________________________________________________________________________________________
•
What have you produced by moving the magnet through the coil?
__________________________________________________________________________________________________
59
60
Find the exhibit Switch logic.
Set up the two different circuits as illustrated on the display panel.
Watch what happens to the light globe in each case when you close the switch.
• What is necessary for electricity to flow in an electric circuit?
Visit activities
Activity set C for Years 9 - 10 & VCE Physics
There are seven different coloured stations in the Megawatt exhibition. You or your
group can choose which one to start at.
_________________________________________________________
Find the exhibit Parallel and series circuits.
Set up two light globes in series and two light globes in parallel as shown in the diagrams below.
Read the WHITE lit panel titled ‘Electricity is everywhere, in everything!
•
Series circuit
In what parts of the body can electricity be found?
Parallel circuit
___________________________________________________________________________
Find the fire ant in the glass case. Read the label inside the glass case to find out why
fire ants can be found throughout this exhibition.
• How do you think fire ants obtained their name?
____________________________________________________________________________
Read about the strange looking shark in the glass
case.
•
What type of shark is it and why is the head shaped like it is?
______________________________________________________________________________
•
What happens when you remove one light globe from the series circuit?
______________________________________________________________________________
_____________________________________________________________________________
•
Read the BLUE lit panel titled ‘Electricity - for communication!’
What happens when you remove one light globe from the parallel circuit?
•
How fast do electrical signals travel?
___________________________________________________________________________
•
Travelling at these speeds, why do we still experience delays in communication?
•
What is the advantage of having electrical appliances in your home connected in parallel?
_____________________________________________________________________________
__________________________________________________________________________
_____________________________________________________________________________
Read the ORANGE lit panel titled ‘Electricity - sustainable energy!’.
•
Look for the different types of cables in the glass case.
• Name two differences between a co-axial cable and an optical fibre cable?
What are some other ways of making electricity other than by burning fossil fuels?
__________________________________________________________________________
_____________________________________________________________________________
Find the exhibit Solar panel. Follow the directions.
•
kilometres per second
_____________________________________________________________________________
What type of energy is being converted to electrical energy?
Find the exhibit Morse code to the rescue?
___________________________________________________________________________
• Use the code below to write down your initials in code.
Tap out your initials in morse code.
Find the exhibit Hydro-micro
•
Follow the directions.
• What type of energy is being converted to electrical energy?
Who invented the first telegraph system?
A._
B_...
C_._.
D_..
E .
F.._.
G__.
H....
I..
___________________________________________________________________________
Find the exhibits Micro-hydro and Wind farm. Follow the directions on both these exhibits
• What type of energy is converted to electrical energy on the wind farm?
___________________________________________________________________________
• What type of energy is converted to electrical energy in the Micro-hydro?
___________________________________________________________________________
65
J
K
L
M
N
O
P
Q
R
.___
_._
._..
__
_.
___
.__.
__._
._.
S ...
T _
U .._
V ..._
W.__
X_.. _
Y _ ._ _
Z __. .
62
Read the GREEN lit panel titled ‘Electricity takes us places!’
Find the exhibit Fax machines.
Follow the directions.
•
•
How does the fax machine work?
Name some vehicles that use electricity to take us places
_________________________________________________________________________________
_____________________________________________________________________________
Find the exhibit Hand battery.
_____________________________________________________________________________
Read the RED label titled ‘ Electricity - a controlled energy supply!’
Put your left hand on the zinc plate and your right hand on the copper plate.
• Write down the meter reading.
• What happens when you put your left hand on the copper plate and your right hand on
the zinc plate? Try to explain the result?
•
What are our main sources of energy for the generation of electricity in power stations?
_______________________________________________________________________________________________
____________________________________________________________________________
____________________________________________________________________________
Look at the sparrow and the possum inside the glass case.
• Read the labels and find out why the sparrow will not get electrocuted sitting on the power
line but the possum may be in trouble.
____________________________________________________________________________
•
What happens when you try two metals that are the same? Try to explain your result?
_________________________________________________________________________________
Find the exhibit Wet cell.
Lower the zinc plate on the left hand side and the copper plate on the right hand side into the liquid.
• Write down the meter reading ______________________________________________________
• You have tried copper and zinc for both the Wet cell and the Hand battery. Are the readings different?
Why?
____________________________________________________________________________
_________________________________________________________________________________
____________________________________________________________________________
_________________________________________________________________________________
Find the exhibit Circles of magnetism.
Read the YELLOW lit panel titled ’Electricity entertains us!’.
Look at the compass needles, then press the yellow button.
• What do you notice about the direction of the compass needles inside the coil compared to
outside the coil?
_____________________________________________________________________________
_____________________________________________________________________________
•
________________________________________________________________________________
Find the exhibit How a speaker works. Follow the directions.
•
Find the exhibit Magnet and coil.
Move the red magnet up and down through the coil of wire.
•
What are some of the things we would have had to do without if we had no electricity
Cross out the incorrect word in the following statements.
(a) Faster/Slower vibrations make higher notes.
(b) Faster/Slower vibrations make lower notes.
What is the effect on the meter?
_____________________________________________________________________________________
Read the PURPLE label titled ‘Electricity - safety at home!’
Move the red magnet up and down again, this time a little faster.
• What is the effect on the meter?
•
What two conditions make electric circuits in the home safe?
1. ______________________________________________________________________________
______________________________________________________________________________________
2. ______________________________________________________________________________
Hold the red magnet still inside the coil of wire.
• What is the effect on the meter?
Find the exhibit Resistance wire.
• Use the probe to supply each of the steel wires (that vary in length) with electricity. Carefully
______________________________________________________________________________________
•
read the meter, then cross out the incorrect word in the following sentence.
(a) The longer the wire, the more/less resistance, the wire has.
Use the probe to supply each of the different metals (of the same length) with electricity.
•
What have you produced by moving the magnet through the coil?
________________________________________________________________________________
63
Order the metals from highest resistance to lowest resistance.
________________________ _______________________ ______________________
64