1. ELECTRICITY

11. + - + + - - - + + + + + + - a) d) c) b) e) f) h)

12. 1.2 Analysing the relationship between electric current and potential difference.

26. 1.3 Analysing Series and Parallel circuit.

27. SERIES CIRCUIT PARALLEL CIRCUIT I 1 = I 2 = I 3 I = I 1 +I 2 + I 3 V = V 1 + V 2 + V 3 V = V 1 = V 2 =V 3 R = R 1 + R 2 + R 3 1/R = 1/R 1 + 1/R 2 + 1/R 3

28. Compare the brightness

29. SERIES CIRCUIT PARALLEL CIRCUIT The brightness of each bulb is equally the same. Brightness of each bulb is greater If one bulb blow out, the circuit is broken. V = V 1 = V 2 =V 3 R = R 1 + R 2 + R 3 1/R = 1/R 1 + 1/R 2 + 1/R 3

31. Compare e.m.f. and potential difference

32. Electromotive force, E Potential difference, V Indicates the electrical energy given to 1 C of charge flowing through the cell or source . Indicates the electrical energy that is transformed to other forms of energy when 1 C of charge passes between two point in a circuit. Represented by the voltmeter reading in an open circuit (when switch is opened) Represented by the voltmeter reading in a closed circuit (when switch is closed) Measured in JC -1 or Volts,V Measured in JC -1 or Volts,V Formula E = I (R + r) (R+r) = total external resistance and total internal resistance Formula V = IR R = Total external resistance

40. These appliances are labeled with values such as 240 V 60 W..What do these labels mean?

41. Electrical energy and Electrical Power

42. E /J V/ V Q /C E /J P/W t/s Electrical energy, E Electrical power, P defined as the ability of the electric current to do work. defined as the rate of energy dissipated or transferred Since V = E/Q Q =It V = IR Since P = E/t E = VIt V = IR Then , E = VIt Then, P = VI and E = I 2 Rt and P = I 2 R P = V 2 R