12/14/2007. Electricity LO:

Transcription

1 Electricity LO:

2 Basic ideas 12/14/2007 Electric current is when electrons start to flow around a circuit. We use an to measure it and it is measured in. Potential difference (also called ) is how big the push on the electrons is. We use a to measure it and it is measured in, a unit named after Volta. Resistance is anything that resists an electric current. It is measured in. WORDS: volts, amps, ohms, voltage, ammeter, voltmeter

3 More basic ideas 12/14/2007

4 More basic ideas 12/14/2007

5 More basic ideas 12/14/2007

6 More basic ideas 12/14/2007

7 More basic ideas 12/14/2007

8 More basic ideas 12/14/2007 If a battery is added the current will because there is a greater on the electrons

9 More basic ideas 12/14/2007 If a battery is added the current will because there is a greater on the electrons

10 More basic ideas 12/14/2007 If a battery is added the current will because there is a greater on the electrons

11 More basic ideas 12/14/2007 If a battery is added the current will because there is a greater on the electrons

12 More basic ideas 12/14/2007 If a battery is added the current will because there is a greater on the electrons

13 More basic ideas 12/14/2007 If a battery is added the current will because there is a greater on the electrons If a bulb is added the current will because there is greater in the circuit

14 Current in a series circuit

15 Current in a series circuit If the current here is 2 amps

16 Current in a series circuit If the current here is 2 amps The current here will be

17 Current in a series circuit If the current here is 2 amps The current here will be The current here will be

18 Current in a series circuit If the current here is 2 amps The current here will be The current here will be And the current here will be

19 In other words, the current in a series circuit is THE SAME at any point 12/14/2007 Current in a series circuit If the current here is 2 amps The current here will be The current here will be And the current here will be

20 Current in a parallel circuit

21 Current in a parallel circuit A PARALLEL circuit is one where the current has a choice of routes

22 Current in a parallel circuit A PARALLEL circuit is one where the current has a choice of routes

23 Current in a parallel circuit A PARALLEL circuit is one where the current has a choice of routes Here comes the current

24 Current in a parallel circuit A PARALLEL circuit is one where the current has a choice of routes Here comes the current Half of the current will go down here (assuming the bulbs are the same)

25 Current in a parallel circuit A PARALLEL circuit is one where the current has a choice of routes Here comes the current Half of the current will go down here (assuming the bulbs are the same) And the rest will go down here

26 Current in a parallel circuit If the current here is 6 amps

27 Current in a parallel circuit If the current here is 6 amps The current here will be

28 Current in a parallel circuit If the current here is 6 amps The current here will be The current here will be

29 Current in a parallel circuit If the current here is 6 amps The current here will be The current here will be The current here will be

30 Current in a parallel circuit If the current here is 6 amps And the current here will be The current here will be The current here will be The current here will be

31 Voltage in a series circuit

32 Voltage in a series circuit If the voltage across the battery is 6V V

33 Voltage in a series circuit If the voltage across the battery is 6V V and these bulbs are all identical

34 Voltage in a series circuit If the voltage across the battery is 6V V and these bulbs are all identical what will the voltage across each bulb be? V V

35 Voltage in a series circuit If the voltage across the battery is 6V V and these bulbs are all identical what will the voltage across each bulb be? V V 2V

36 Voltage in a series circuit If the voltage across the battery is 6V V

37 Voltage in a series circuit If the voltage across the battery is 6V V V

38 Voltage in a series circuit If the voltage across the battery is 6V V what will the voltage across two bulbs be? V

39 Voltage in a series circuit If the voltage across the battery is 6V V what will the voltage across two bulbs be? V 4V

40 Voltage in a parallel circuit

41 Voltage in a parallel circuit If the voltage across the batteries is 4V

42 Voltage in a parallel circuit If the voltage across the batteries is 4V V What is the voltage here?

43 Voltage in a parallel circuit If the voltage across the batteries is 4V V What is the voltage here? And here? V

44 Voltage in a parallel circuit If the voltage across the batteries is 4V V What is the voltage here? 4V V And here?

45 Voltage in a parallel circuit If the voltage across the batteries is 4V V What is the voltage here? 4V V And here? 4V

46 Summary 12/14/2007

47 Summary 12/14/2007 In a SERIES circuit: Current is THE SAME at any point Voltage SPLITS UP over each component

48 Voltage is THE SAME across each strand Summary 12/14/2007 In a SERIES circuit: Current is THE SAME at any point Voltage SPLITS UP over each component In a PARALLEL circuit: Current SPLITS UP down each strand

49 An example question: 12/14/2007 3A 6V A 3 A 1 V 1 A 2 V 2 V 3

50 Advantages of parallel circuits

51 Advantages of parallel circuits There are two main reasons why parallel circuits are used more commonly than series circuits:

52 Advantages of parallel circuits There are two main reasons why parallel circuits are used more commonly than series circuits: 1) Extra appliances (like bulbs) can be added without affecting the output of the others

53 Advantages of parallel circuits There are two main reasons why parallel circuits are used more commonly than series circuits: 1) Extra appliances (like bulbs) can be added without affecting the output of the others 2) If one appliance breaks it won t affect the others either