Electricity

Electricity is a central part of everyday life. It is found in the home, work and community.  It runs appliances and can be extremely dangerous. It also forms the basis of an important global issue – what is the best way to generate electricity? Fossil fuels (such as coal) are burned to produce most of the world's electricity but also release carbon dioxide into the atmosphere, which contributes to global warming. 

Electricity is a good example of a topic that can be quite interesting (see real world examples below) but is often made boring with information overload, in particular on electrical circuits. A small percentage of students will become electricians so it's more important to focus on real world issues such as safety with electricity in the home.

 

Online Resources               Home    Physics    Top               Previous    Next

 

  • Learning Power– Southern Electric Company – excellent interactive website with nice graphics and three excellent interactives 
    • How Plants Work – takes a look at three ways to generate electricity – nuclear power, gas and coal power and hydropower
    • Energy Use Looker Upper – looks at common household electrical items and tells you how much power they use 
    • Electric Safety – looks at a town where students click on the hazards signs to learn about the common dangers of electricity and what they should do to keep safe. Comes with a nice Q & A section on the second tab
  • PhET – University of Colorado – a series of simple interactives on electrical circuits
  • Bolbz Guide to Electric Circuits – Andy Thelwell – excellent interactive about circuits that involves great information and games and quizzes
  • Launchball – Science Museum of London – games that need to use logic and knowledge of physics to get a ball in a hole including electromagnets and generators
  • Light-Emitting Diode Operation – Zeiss Online Campus – nice interactive showing how a light-emitting diode (LED) works
  • Save the World – Wonderville – excellent tutorials and interactive game on renewable energy that explains electricity generators and how electricity is generated from solar power, geothermal, tidal, wind power and hydroelectricity. Students go around the world choosing the most appropriate renewable energy sources for the region 
  • Solar Panels – Sumanas – photovoltaic effect
  • Techville Museum – Nobelprize.org – a 1980's-style graphics game where students move from room to room and learn about the Integrated Circuit. This is a long and slow game but students will still enjoy it.

 

Real World               Home    Physics    Top               Previous    Next

 

  • arc welder – a power tool that creates an electric arc (current) between an electrode on the arc welder and the metal, which melts and welds the metal. An electric arc is an electrical breakdown of gas that produces a current of plasma that releases light. 
  • batteries – also known as electrochemical cells – a means of generating electricity using chemical reactions
  • bug zappers – a protective cage with a fluorescent lamp that produces UV light, which attracts insects. A high voltage power supply (2,000 volts) kills the insects.
  • computer chips – also called integrated circuits – electronic circuits where all the components (transistors, diodes, resistors and capacitors) are manufactured on the thin surface of a semiconductor
  • Christmas lights – a circuit in series
  • computer – a device which can be programmed to carry out a finite number of operations. The first electronic digital computers were developed between 1940 and 1945 in the U.K. and U.S. They were the size of a large room and consumed as much power as several hundred modern PCs. Modern computers are millions to billions times more powerful and multiple times smaller. Embedded computers now power devices from mobile phones and mp3 players to fighter jets.
  • digital TV – the transmission of audio and visual information using digital signals
  • electrocution
  • generation – fueled by combustion or nuclear fission, which produces heat energy that drives heat engines, which drives electromechanical generators. Combustion results in the production of carbon dioxide and water vapour, whereas nuclear fission heats water into steam. Heat engines use the rapid expansion of gas to perform mechanical work. An electric generator is a device that converts mechanical energy into electrical energy. The movement of copper between two poles of a magnet causes electricity to be produced in the copper. The generator forces electrons to flow through an external electric circuit – this is electricity.
  • heat – resistance
    • toaster
    • heater
    • kettle
    • clothes dryer
  • home – in parallel
  • hydroelectric dams
  • levitating trains – superconductors
  • lie detector
  • light bulb – electrical energy is converted into light energy
  • lightning – see Light
  • neurons
  • overload
  • power lines
  • power point – active, neutral and earth
  • power station
  • robots – artificial intelligence (A.I.)
  • safety switch
  • silicon chip – semiconductor
  • speakers
  • street lights – a circuit in parallel
  • switch – light switch
  • TV
    • analog TV
    • digital TV
      • set top box – a device that allows viewers to use their current analog TVs to receive digital signals
    • plasma TV
    • LCD TV
  • wind farms – the motion of wind turbines

 

Key Knowledge               Home    Physics    Top               Previous    Next

 

Science in the Real World

 

  • why do we use electricity?
    • electricity is a means to transport energy from where it is produced to where it is needed
    • electrical energy (electricity) is converted by our appliances into useful forms of energy – light, heat, sound and movement
  • how to save electricity
    • unplug appliances – even appliances that are turned off draw electricity
  • electrical safety
    • not overloading powerpoints

 

Science as a Career

 

  • electricity
  • current – the flow of charge (usually electrons) – measured in amperes (amps) (A) or milliamps (mA)
  • voltage – the energy difference between point A and point B – the energy used to move electrons – measured in volts (V)
  • resistance – a measure of how difficult it is for electrons to pass through a wire – measured in Ohms (Ω)
  • power sources
    • electricity – power point
    • battery
  • in series – one path – one wire – one circuit
  • in parallel – two or more paths – two or more wires – two or more circuits
  • two loads (e.g. light bulbs)
    • in series
      • one circuit – the current and voltage is shared = less brighter
      • one circuit – less energy used
    • in parallel
      • two circuits – two currents – two voltages – more brightness
      • two circuits – twice as much energy is used
  • advantages
    • in series – less wire
    • in parallel – if one light goes out, the other lights still work
  • 4 things you need to make an electric circuit work
    • energy source
    • load
    • wires
    • control
  • electric components and symbols
    • battery (single cell)
    • two batteries (two cells)
    • globe
    • switch
    • ammeter
    • voltmeter
    • transformer – transfers energy from one circuit to another
    • capacitor – stores electrical energy
    • transistor – a semiconductor used to amplify and switch electronic signals. It contains at least three terminals
    • resistor – a two terminal component
    • diode – a two terminal component that conducts electric current in one direction (the forward direction) and hence blocks it in the reverse direction
  • power – energy used per second – measured in watts (W) or kilowatts (kW)
  • conductor – a substance that conducts electricity, e.g. copper wire
  • insulator – a substance that does not conduct electricity, e.g. plastic
  • superconductor – a substance whose resistance becomes zero at very low temperatures and thus is able to conduct huge currents
  • semiconductor – a substance that is quite a poor conductor but whose conductivity improves when small amounts of material are added, i.e. it is between a conductor and insulator
  • 3 meters
    • ammeter – measures current
    • voltmeter – measures voltage
    • multimeter – measures current, voltage and resistance
  • Ohm’s law – Voltage (V) = Current (I) x Resistance (R)
  • AC/DC – alternating current/direct current

 

Topic Ideas               Home    Physics    Top               Previous    Next

 

  • Van der Graaf generator
  • LED ice cubes
  • cartoons on circuits – need to search web
  • Save our city! List the advantages and disadvantages of alternative sources of energy. Research internet.
  • Make your own kettle. p. 98. Science Links 1. Low voltage DC power supply (4V), 150 mL beaker, 40 cm Nichrome wire, pencil or biro, leads, thermometer. Results and discussion. Record temperature every minute over 10 minutes. Did the temperature decrease, increase or stay the same? Show this using a graph of temp vs minutes. Electrical energy was converted into _____ energy. List 3 other things at home that use electricity in this way. Extension. Do you think this kettle would be efficient enough to use at home? List 3 ways to improve the design of your kettle to make it more efficient and test these with your teacher’s permission.
  • bring in some old electrical appliances and rip them apart, e.g. radio
  • why can birds sit on a powerline?
  • assignment – how to save electricity. Questions on the assignment include why it is important to save electricity and ways it can be saved

 

Images               Home    Physics    Top               Previous    Next

 

  • Seen an amazing image? Let me know! Contact me here. Please remember that I need permission to use images on this website. So if you can provide a link to the original image or even the credits (author, title, URL) and confirmation that I have permission to use the image that would be great.

Comments

 
#1 Shantae 2014-06-29 00:48
You're soo awesome! I don't suppose I've tгuly read a singlee thing lіke that Ьefore.
Ѕo ցreat toο find sοmeone with a fеw unique thoսghts on this issue.
Really.. thank yоu fߋr starting tҺis up. This site is ѕomething that is needed οn the internet,
someone ԝith a bit οf originality!

Ңere iis my web рage :: swift cover
Insurance Phone number: http://www.swiftcoverinsurancenumber.co.uk
Quote
 
 
#2 Alethea 2014-07-20 03:11
I've skid through a few of your site post and also I could only
come across awesome content articles as well as nothing at all a
smaller amount.

my web site ... Isachar Alva: http://solarpanel-training.com/what-are-solar-panels.html
Quote
 

Add comment

Security code
Refresh