Wiring Part 2 : circuits
- 1. Circuits Energy & Environment This PowerPoint is created and developed by :
- 2. Simple Circuit What symbols are shown here Connect and what do they do? circuit Wire together Power Source -ve Electricity to Light Purpose G Battery +ve Lamp Safety Fuse Switch Controlling Device Device
- 3. Closed Circuit For current to flow round Where is there potential difference circuit, must be a connecting path & where is there resistance? -ve Some Potential resistance G Potential difference difference +ve Low resistance
- 4. Where is there potential difference Current stops as doesn’t have a & where is there resistance? complete path No power used -ve G Open circuit +ve Very high resistance Examples of open circuit
- 5. Short Circuit Why does the current chose to go this way? -ve Some resistance Almost no G resistance +ve Circuits are protected against Results in excessive current excessive current by fuses Which can cause overheating and damage.
- 6. Where could we put this bulb if we want to add it in series? -ve G Series Circuit +ve
- 7. Series Circuit: Current -ve B =4 amps In a series circuit the current is the same G across the circuit A =4 amps +ve Itotal=I1=I2=I3 Current through switch=4 amps If the current through the switch is 4 amps, what is the current through the light bulb A and B?
- 8. Series Circuit: Voltage The potential difference in EMF across two points is called the potential In a series circuit the voltage is difference. the sum of the EMF This side A This side B =6 volts -ve 12 volts EMF= 12 volts=6 +6 12 G volts A =6 volts +ve (EMF)vtotal=V1+V2+V3 B
- 9. Series Circuit: Voltage What happens when we add another bulb? What is the voltage of each In a series circuit the voltage is identical bulb. the sum of the EMF This side A This side C =4 volts -ve B =4 volts 12 volts EMF= 12 volts 12 G volts 12 volts= 3 x light bulbs A =4 volts +ve Light bulb = 12 volts 3 =4 volts each (EMF)vtotal=V1+V2+V3 B
- 10. Series Circuits If this bulb blows what happens to the other bulbs? The circuit is open so there is no path for the current to travel. If current=0 Power=0 As power=EMF x Current
- 11. Parallel Circuit Where could we put this bulb if we want to add it in parallel? -ve G +ve
- 12. Parallel Circuit: Current In a parallel circuit the current is split up throughout the different branches -ve B =2 amps Itotal=I1+I2+I3 G A =2 amps +ve Current through switch=4 amps If the current through the switch is 4 amps, what is the current through the identical light bulbs A and B?
- 13. Parallel Circuit: Voltage The potential difference in EMF across Voltage in parallel circuits is equal two points is called the potential across branches difference. This side This side A A A 1.5 volts -ve Voltage =1.5 volts G1.5 volts 1.5 volts 1.5 volts +ve B B B
- 14. Parallel Circuit: Voltage Voltage in parallel circuits is equal What happens when we add another bulb? This side A A A A 1.5 1.5 1.5 volts -ve volts volts Voltage =1.5 volts G1.5 volts +ve B B B B (EMF)vtotal=V1=V2=V3
- 15. Parallel Circuits If this bulb blows what happens to the other bulbs? The circuit for that bulb is open but the circuit for the other two bulbs is ok