* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download KS4 Electricity – Simple Circuits
Survey
Document related concepts
Power MOSFET wikipedia , lookup
Electric battery wikipedia , lookup
Valve RF amplifier wikipedia , lookup
Schmitt trigger wikipedia , lookup
Nanogenerator wikipedia , lookup
Switched-mode power supply wikipedia , lookup
Operational amplifier wikipedia , lookup
Index of electronics articles wikipedia , lookup
Regenerative circuit wikipedia , lookup
Resistive opto-isolator wikipedia , lookup
Flexible electronics wikipedia , lookup
Current source wikipedia , lookup
Integrated circuit wikipedia , lookup
Surge protector wikipedia , lookup
Current mirror wikipedia , lookup
Rectiverter wikipedia , lookup
RLC circuit wikipedia , lookup
Transcript
KS4 Electricity – Simple Circuits © Boardworks Ltd 2003 Teacher’s Notes A slide contains teacher’s notes wherever this icon is displayed - To access these notes go to ‘Notes Page View’ (PowerPoint 97) or ‘Normal View’ (PowerPoint 2000). Notes Page View Normal View Flash Files A flash file has been embedded into the PowerPoint slide wherever this icon is displayed – These files are not editable. © Boardworks Ltd 2003 Circuit symbols Instead of drawing intricate diagrams of electrical components we use circuit symbols to simplify how circuits are set up. You will need to learn these, how to draw them, and how to identify them. Filament lamp © Boardworks Ltd 2003 Use a textbook or other resource to fill in the table below: Component Circuit symbol Fuse Resistor Motor M Switch © Boardworks Ltd 2003 Use a textbook or other resource to fill in the table below: Component Circuit symbol Cell Battery Ammeter A Voltmeter V © Boardworks Ltd 2003 Breaks in circuits Set up the circuit shown…. …does the bulb light? NO Why does the bulb not light? There is a break in the circuit. For electricity to flow in a circuit it must be able to flow from one terminal of the cell or battery to the other terminal. © Boardworks Ltd 2003 Letting electricity pass Do all materials let electricity pass? Which materials will and which materials will not? Set up the circuit shown and place different materials in the gap in the circuit. Record which materials let electricity through (the bulb lights if electricity flows). What do we call a material that lets electricity flow through it? CONDUCTOR What do we call a material that does not let electricity flow through it? INSULATOR © Boardworks Ltd 2003 Which of these bulbs will light? Build the circuits! Electricity will always take the easiest path. A. B. C. x x It is easier to flow through a wire than through the bulb. So in circuits B and C the electricity does not pass through the bulb. The cell or battery still loses energy because , electricity is still flowing. This type of circuit is known as a SHORT CIRCUIT. © Boardworks Ltd 2003 Electron flow Electricity in wires is a flow of electrons along the wire. What do we call this flow of electrons? Electrical current © Boardworks Ltd 2003 Current Flow When we talk about current flowing we say that current flows out of the positive terminal of the cell and back into the negative terminal. Conventional Current What do we call this flow? © Boardworks Ltd 2003 Electron Flow However, the electrons flow from the negative side of the battery to the positive side. These are the particles which are actually moving through the conductor. © Boardworks Ltd 2003 Conventional current and Electron flow Whenwill What charge do electrons two a positive negative do were electrons and discovered, charges a negative have? do physicists worked out what if charge placed was donear really to each tohappening. each other? other? Negative They will attract repel each eachother. other. Negatively charged electrons are repelled out of the negative terminal of the cell. They then travel round the circuit and are attracted back to the positive terminal. Conventional current electrons Conventional current © Boardworks Ltd 2003 Current In an electric c____, ircuit current is the flow of e_______. ore lectrons The bigger the current, the m___ electrons are flowing around the circuit. The w___ ires carry the electrons from one terminal erminal around the circuit to the other t______. lamps © Boardworks Ltd 2003 Set up the two circuits shown: A. BRIGHTER B. DIMMER What do happens The Series we Parallel In circuit call other ifare Circuit circuit you Circuit circuit Athe bulb the unscrew B? A? bulbs staysthe goes out. lit. are a one bulb the bulb inbrightest. circuit in Circuit B? A? In which circuit bulbs brightest? © Boardworks Ltd 2003 Measuring current I In a series circuit the current is the same Set up theyou circuit shown below…… …and The What current then do record isnotice the the same about current for the each using readings? ammeter. an ammeter wherever you measure it. in the places shown below. When measuring current ammeters are always placed in series. A A A © Boardworks Ltd 2003 Measuring current II For a parallel circuit, the current that leaves the cell or battery is the same as the that returns to at the cellreadings? or battery.shown. The current does not get …then What record you the notice current about the the locations Setcurrent updo the circuit shown below…… used up by a circuit, just the energy the electrons are carrying. A1 = A4 A1 Ammeter Current (A) A1 A2 A3 A4 0.8 0.4 0.4 A4 A2 A3 The sum of the currents in the branches of a parallel circuit is the equal to the current that leaves the cell or battery. A1 = A2 + A3 =A4 0.8 © Boardworks Ltd 2003 Voltage oltage is a measure of how big a push The v_____ lectrons are given as they leave the the e_______ attery The bigger the voltage, the cell or b_____. ush bigger the p___. ower s_____ upply produces The cell, battery or p____ the voltage. lamps © Boardworks Ltd 2003 Measuring voltage I For a series circuit, the sum of the voltages for each component is equal todo theyou voltage across the orlocations battery. shown. Set up the apparatus as shown…… …then What record notice the voltages about the atcell the readings? V1 = V2 + V3 V1 NB Voltmeters are connected in parallel V2 Voltmeter Voltage (V) V1 V2 V3 1.5 0.75 0.75 V3 © Boardworks Ltd 2003 Series circuit © Boardworks Ltd 2003 Measuring voltage II V1 For ..measure parallel circuit, voltage theat Setado up thethe apparatus What you notice about the voltage locations across shown. the as shown…. your readings? cell/battery is the same as the voltage across each branch. V1 = V2 = V3 V2 V3 Voltmeter Voltage (V) V1 V2 V3 1.5 1.5 1.5 © Boardworks Ltd 2003 Parallel circuits © Boardworks Ltd 2003 Name this circuit symbol. V A. Ammeter B. Switch C. Bulb D. Voltmeter © Boardworks Ltd 2003 What component is used to measure electrical current? A. Switch B. Resistor C. Ammeter D. Voltmeter © Boardworks Ltd 2003 Which component changes electrical energy into light energy? A. Bulb B. Switch C. Cell D. Battery © Boardworks Ltd 2003 Which component is a store of chemical energy? A. Bulb B. Battery C. Switch D. Resistor © Boardworks Ltd 2003 Which of these materials is not a conductor of electricity? A. Water B. Graphite C. Lead D. Wood © Boardworks Ltd 2003