1. ELECTRICITY We uses enery everyday, we transfer energy in lots of ways every day. When a room is dark, we switch on the light. The light bulb transfers energy to the room. Electricity is a type of energy that can build up in one place or flow from one place to another. When electricity is in one place is called as static electricity (the word static means something that does not move); electricity that moves from one place to another is called current electricity. When a room is dark we switch on the light 1.2. Electrical charges There are two types of electrical charge: positive and negative. Negative charges can move from one place or an object to another. Objects have positive and negative charges. If an object has more negative than positive charges, it is negatively charged. If an object has more positive than negative charges, it is positively charged. If an object has the same number of positive and negative charges, it is neutral. Objects with opposite charges attract each other. Objects with the same charges repel each other Objects with opposite charges attract each other, on the contrary, objects with the same charges repel each other. By MACS 1
1.3. Static Electricity Static electricity often happens when we rub things together. When we rub an object with something made from a different material, we make electrical charges move, creating static electricity. Static electricity occurs with materials which are insulators. For example, if we rub a balloon onto our hair, negative charges move from our hair onto the balloon. Our hair becomes positively charged and the balloon becomes en negatively charged. When we rub an object with something made from a different material static electricity is created Electricity is a type of energy that can build up in one place or flow from one place to another. There are two types of electricity: static and current electricity. There are two types of electrical charge: positive and negative. Objects with opposite charges attract each other, on the contrary, objects with the same charges repel each other. Static electricity often happens when you rub things together. By MACS 2
ACTIVITIES 1. Draw on your notebook and colour to: Attract Repel 2. Complete with the words of the box negatively repel neutral positively attract Objects with the same charges.. each other. If an object has more positive charges than negative charges, it is charged. If an object has more negative charges than positive charges, it is charged. If an object has the same number of positive and negative charges, it is. Objects with opposite charges.. each other. 3. Read and complete the text. Electricity is a type of that can build up in one place or flow from one place to another. We can difference two types of electricity:.. electricity and static electricity. With respect to charges, there. also two types: positive and... An object is charged positively when has more than negative charges, on the contrary an object is charged. when has more negative than positive charges... electricity happens when we rub things together. Static electricity occurs with materials which are. By MACS 3
2. Electrical current Electrical current is the flow of electrical charges. It transmits energy called electricity. When electrons move, they carry electrical energy from one place to another. This is called current electricity or an electric current. A lightning bolt is one example of an electric current. Electric current passes easily through some materials. These materials are conductors. Many metals (iron, copper, steel, aluminium ) and water are good conductors. Electric current does not pass easily through other materials: air, rubber, glass, plastic and wood. These materials are insulators. Wires are made up of conductors (copper) and insulators (plastic) Conductors good conductors of electricity metals Insulators bad conductors of electricity air rubber, plastic, glass 3. Electric circuits An electric circuit is a set of different components which are connected each other to allow the flow of an electrical current. The main components of an electric circuit are: a generator, an electrical component, wires and a switch. By MACS 4
Generator: is the source of electricity, for example a battery. Electrical component: such as a light bulb or a motor. Wires. A switch which control the flow of electrical current. switch generator wires electrical component 3.1. Types of electric circuits There are two types of basic circuits are open and closed. A closed circuit allows the movement of electrical energy. An open circuit does not allow the electric current to flow. The two types of closed circuits are parallel and series. In a parallel circuit, there are two or more pathways for electric current to flow. If one pathway is opened, the other one still works. In a series circuit, there is only one pathway for electricity. If it is open the flow of current stops. By MACS 5
Series circuit Parallel circuit Electrical current is the flow of electrical charges. It transmits energy called electricity. Conductors are good conductors of electricity, insulators are bad conductors of electricity. An electric circuit is a set of different components which are connected each other to allow the flow of an electrical current, the components are: generator, wires, switch and an electrical component. There are two types of basic circuits, open and closed. The two types of closed circuits are: parallel and series. By MACS 6
ACTIVITIES 4. Read and write, true (T) or false (F) A closed circuit does not allow the electric current to flow. Conductors are materials that electrical energy moves through easily. Insulators are materials that allow electric current to pass easily. The main components of an electric circuit are: a generator, an electrical component, wires and a car. Examples of insulators are: plastic, rubber and water. 5. Change the false sentences into true sentences. 6. Read and match. 1. closed circuit A. is the source of electricity. 2. series circuit B. occurs when we rub an object with something made from a different material. 3. open circuit C. a circuit with two or more pathways for electric current to flow. 4. insulators D. controls the flow of electrical current. 5. parallel circuit E. is the flow of electrical charges. 6. electrical current F. are good conductors of electricity. 7. switch G. allows the movement of electrical energy. 8. conductors H. does not allow the electric current to flow. 9. generator I. are bad conductors of electricity. 10. Static electricity J. is a circuit with only one pathway for electricity. By MACS 7
7. Draw a circuit with its components in your notebook. 8. Look at the pictures. Write their names. Are they conductors or insulators? 1 2 3 4 5 6 7 8 Never stick scissors, pens, fingers or anything else into a mains socket. Never touch switches with wet hands. Never use electrical appliances near water. Always hold the plastic part of a plug when plugging in and unplugging appliances. By MACS 8
4. MAGNETISM A phenomenon apparently related to electricity is magnetism. We are familiar with magnetism through the interaction of compasses with the earth s magnetic field, or through fridge magnets or magnets on children s toys. Magnets can be natural, as the mineral magnetite, or Mineral Magnetite artificial, such as different magnets manufactured from metal. A magnet is any object that has a magnetic field Magnetic forces are explained very similar to electric forces, there are two types of magnetic poles, called North and South. Like poles repel. Opposite poles attract. Magnetic forces are explained similar to electric forces 4.1. Magnetic fields Magnets create magnetic fields. A magnetic field is the space around a magnet where materials, such as iron filings, are affected by magnetic forces. A magnetic field 4.2. The uses of magnets Magnets are used to make electric motors and generators. Without these electric motors and generators we would not have telephones, lights, electric heat, television, or computers. We classify magnets according to their use: Electromagnets: they are used in televisions, computer monitors and microphones. Magnetic strips: in credit cards. Magnetic recording media: they are used in radio cassettes, floppy disks and hard disks. By MACS 9
Magnets can be natural or artificial. There are two types of magnetic poles, called North and South. Like poles repeal and opposite poles attract. Magnets create magnetic fields. A magnetic field is the space around a magnet where materials are affected by magnetic forces. According to their use we can classify magnets into: electromagnets, magnetic strips and magnetic recording media. ACTIVITIES 9. How can you be careful with electricity? Put in order and write sentences. fingers stick your mains Never socket or metal objects into a. switches touch hands with wet Never. use Never near appliances electrical water. part Always plastic hold the of plug a. 10. Read and write the correct word from the box. cards televisions generators field magnetic field natural South recording Magnetics scrips are used in credit. Magnets can be. and artificial. A magnet is an object that has a magnetic. There are two of magnetic poles: North and.. Magnets are used in electric motors and.. Radio cassettes, floppy disks or hard disks use magnetic.. media.is the space around a magnet where some materials, such as iron filings, are affected by magnetic forces. Electromagnets are used in, computer monitors or microphones. By MACS 10
11. Complete the table on your notebook. Classify these magnets. Electromagnets Magnetic strips Magnetic recording media Floppy disk video cassetted speakers memory card hard disk magnetic strip Computer monitor microphone television credit card By MACS 11
5. ELECTRICITY 5.1. Electricity production Human beings need to generate electricity lo live better. Electricity is produced at power plants or power stations. How is electricity generated? Water, steam or wind moves a turbine that is Coal station. Coal is used to produce energy connected to a generator, when the turbine rotates, the generator transforms mechanical energy into electricity, using a magnetic field and a conductor. We use different energy sources to move the turbine. Some power stations use non-renewable energies (coal, petrol.) and others use renewable energies (wind, water or sun). Solar station. Sunlight is used to produce energy By MACS 12
5.2. Electricity production The generated electricity at power stations is transmitted through conducting wires to substations near populated areas or villages. It is transmitted through tall towers called high-tension power transmission lines. A high tension power transmission line 5.3. Electricity distribution and consumption The electricity is distributed through power lines to industries, houses, offices and other places. Electricity produce different forms of energy: Heat energy: radiators, toaster Light energy: televisions, lamps Sound energy: mobile phones, radio cassettes, televisions Applicances that use different forms of energy Movement energy: cars, whisk mixer, train Electricity is generated through a turbine that is connected to a generator, when the turbine rotates, the generator transforms mechanical energy into electricity, using a magnetic field and a conductor. Electricity is transmitted through tall towers called high-tension power transmission lines. Electricity is used by different appliances to produce: heat, movement, light an sound. By MACS 13
6. HISTORICAL CONTRIBUTIONS TO ELECTRICITY Benjamin Franklin was a respected statesman and scientist. His scientific experiments proved that lightning is a form of electricity. Franklin also helped develop the lightning rod, a device used to protect buildings from damage during electric storms. Thomas Edison invented the incandescent light and the phonograph. He made improvements to the telephone, typewriter, electric generator, and electrically powered train. He designed the world s first electric power stations, thereby making electric power available to millions. Michael Faraday was a British physicist and chemist who discovered the principle of electromagnetic induction in 1831. He found that moving a magnet through a coil of copper wire caused an electric current to flow in the wire (induction). The electric generator and electric motor are based on this principle By MACS 14
ACTIVITIES 12. Explain. How is electricity generated? 13. Read and tick. Renewable or non renewable energy. By MACS 15
14. Read and match. 1. Solar A. heat from within the Earth 2. Coal B. energy coming from the sun 3. Wind C. oil from the Earth 4. Nuclear D. air in motion. 5. Biomass E. energy from moving water 6. Petroleum F. a sedimentary rock composed mainly of carbon 7. Natural gas G. organic materials made from plants and animals 8. Geothermal H. energy in the nucleus of a atom 9. Hydropower I. methane from the Earth 15. What type of energy do they produce? Classify. toaster television radio computer train Washing machine hairdryer radiator oven lamp mixer By MACS 16
16. What did they invented? Make sentences. Use Internet if necessary. Benjamin Franklin Thomas Edison Michael Faraday Benjamin Franklin invented.. 17. Classify in renewable or non-renewable energies. petroleum solar biomass geothermal wind coal natural gas nuclear hydropower RENEWABLE ENERGY NON-RENEWABLE ENERGY 18. What can you do to save energy? Use these webpages http://www.ecohusky.uconn.edu/dormtips.htm http://www.ecomall.com/greenshopping/20things.htm http://www.nrdc.org/air/energy/genergy.asp 19. Ask to your classmate. QUESTIONS Ask about his/her name Ask about his/her age Ask about where he/she lives YOUR CLASSMATE ANSWERS By MACS 17
Ask about appliances that use electricity Ask about appliances that use batteries 20. Draw a series and a parallel circuit on your notebook. Write the name of the components. 21. Put the letters in order and find the word. 1. ATCSIT 2. PLERE 3. TATRACT 4. TUCORDCON 5. LASUINTOR 6. AETNMG 7. RECNTUR 8. EOLP By MACS 18
22. Name these objects. Do they use electricity or a battery? computer Example: lamp electricity 23. Choose the correct answer. Final test!! 1. When electricity is in one place is called a) Current electricity b) Static electricity c) Parallel electricity By MACS 19
2. When electricity moves from one place to another is called a) Magnetism b) Static electricity c) Current electricity 3. If an object has more negative than positive charges a) It is positively charged b) It is negatively charged c) It is neutral 4. Objects with opposite charges a) Repel each other b) Play each other c) Attract each other 5. Static electricity often happens a) When we join two metals b) When we rub an object with something made from a different material c) When we rub two conductor materials 6. Static electricity occurs with materials which are a) Conductors b) Insulators c) Magnets 7. Insulators are a) Good conductors of electricity b) Bad conductors of electricity c) Materials that attract other materials By MACS 20
8. Copper is a a) Insulator material b) Conductor material c) Type of magnet 9. An electric circuit is a) Different materials which do not allow the flow of an electrical current b) a high tension power plant c) a set of different components which are connected each other to allow the flow of an electrical current 10. The components of an electric circuit are a) rubber, plastic and wood b) A generator, an electrical component, wires and a switch c) A magnet, wires, motor and a computer 11. Rubber, plastic and wood are a) Insulator materials b) Conductors materials c) Neutral materials 12. A closed circuit allows a) The movement of energy sources b) The attraction of two materials c) The movement of electrical energy 13. There are two types of closed circuits a) Open and closed circuits b) Parallel and series circuits c) Magnets and current circuits 14. In a parallel circuit a) There are two or more pathways for electric current to flow b) There is only a pathway c) There is not any pathway By MACS 21
15. A magnet is a) An object composed of an insulator material b) A component of an electric circuit c) An object that has a magnetic field 16. A magnetic field is a) An object that has magnetic properties b) the space around a magnet where materials are affected by magnetic forces c) A power station to produce energy 17. Credit cards are composed of a) electromagnets b) magnetic strips c) magnetic recording media 18. A radio produces a) Light energy b) Sound energy c) Heat energy 19. Renewable energies are a) Coal, nuclear and natural gas energies. b) Nuclear, biomass and solar energies. c) Solar, biomass, hydropower, wind and geothermal energies. 20. Thomas Edison invented a) The lightning rod b) The incandescent light c) The electric generator By MACS 22
To transfer: Plastic: Heat: To switch on: Wood: Electromagnets: Light bulb: To allow: Magnetic strips: Wind: Component: Magnetic recording media: To build up: Generator: To generate: Static electricity: Conducting wires: Power plants: Current electricity: Switch: Power Stations: Electrical charge: Closed circuit: Renewable energy: charge: Open circuit: Non-renewable energy: positive: Parallel circuit: Hydropower energy: negative: Seires circuit: Solar energy: neutral: Pathway: Biomass energy: To attract: Still: Wind energy: To repel: To work: Geothermal energy: To rub: Current: Turbine: Insulator: Never: To rotate: Conductor: Always: Energy source: Balloon: To touch: High tension: To become: To plug: Transmission line: Electrical current: To Unplug: Heat energy: To flow: Main socket: Light energy: Lightning bolt: Wet: Movement energy: To pass: Magnetism: Sound energy: Easily: Compass: Lightning rod: Iron: Magnet: Buildings: Copper: Magnetic field: Electric storm: Steel: Pole: Incandescente light: Aluminium: North: Improvement: Rubber: South: Available: Glass: Magnetic forces: Chemist: By MACS 23