Principle of electricity


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Principle of electricity

  1. 1. Principle of Electrical Presenter: Noraide Md Yusop Rosazmir Mat Rashid Mohd Norhisham Nordin Azhar Md Saad Chin Seng Fatt
  2. 2. Contents 1 Electrical Circuit 2 Ohm’s Law 3 Series & Parallel Circuit 4 Measuring Current 5 Measuring Voltage 6 Conclusion
  3. 3. ELECTRICAL CIRCUITS All you need to be an inventor is a good imagination and a pile of junk. -Thomas Edison
  4. 4. Ohm’s Law I=V/R I V = Voltage (Volts) R Georg Simon Ohm (1787-1854) = Current (Amperes) (amps) = Resistance (ohms)
  5. 5. How you should be thinking about electric circuits: Voltage: a force that pushes the current through the circuit (in this picture it would be equivalent to gravity)
  6. 6. How you should be thinking about electric circuits: Resistance: friction that impedes flow of current through the circuit (rocks in the river)
  7. 7. How you should be thinking about electric circuits: Current: the actual “substance” that is flowing through the wires of the circuit (electrons!)
  8. 8. Would This Work?
  9. 9. Would This Work?
  10. 10. Would This Work?
  11. 11. The Central Concept: Closed Circuit
  12. 12. circuit diagram Scientists usually draw electric circuits using symbols; cell lamp switch wires
  13. 13. Ohm’s Law Simulation Click Here
  14. 14. Series and Parallel Circuits Series Circuits  only one end of each component is connected  e.g. Christmas tree lights Parallel Circuits  both ends of a component are connected  e.g. household lighting
  15. 15. series circuit • voltage is shared between the components 3V 1.5V 1.5V
  16. 16. parallel circuit • voltage is the same in all parts of the circuit. 3V 3V 3V
  17. 17. Simple Circuits Series circuit  All in a row  1 path for electricity  1 light goes out and the circuit is broken Parallel circuit  Many paths for electricity  1 light goes out and the others stay on
  18. 18. measuring current Electric current is measured in amps (A) using an ammeter connected in series in the circuit. A
  19. 19. measuring current This is how we draw an ammeter in a circuit. A A SERIES CIRCUIT PARALLEL CIRCUIT
  20. 20. measuring current SERIES CIRCUIT • current is the same at all points in the circuit. 2A 2A 2A PARALLEL CIRCUIT • current is shared between the components 2A 2A 1A 1A
  21. 21. measuring voltage The ‘electrical push’ which the cell gives to the current is called the voltage. It is measured in volts (V) on a voltmeter V
  22. 22. measuring voltage This is how we draw a voltmeter in a circuit. V SERIES CIRCUIT V PARALLEL CIRCUIT
  23. 23. measuring voltage Different cells produce different voltages. The bigger the voltage supplied by the cell, the bigger the current. Unlike an ammeter, a voltmeter is connected across the components Scientist usually use the term Potential Difference (pd) when they talk about voltage.
  24. 24. Conclusion Ohm law is V = I / R Electric circuit has two types of connection  Series circuit  Parallel circuit • Voltage is measured using voltmeter by connected across the components • Current is measured using ammeter by connected in series in the circuit.
  25. 25. The End