1. Electric symbols

3. Cell and battery of cells

5. Lamp

7. Switch

9. Ammeter

11. Voltmeter

13. Resistor

15. Variable resistor (rheostat)

17. Bell/buzzer

19. Thermistor Resistance decreases with increasing temperature Temp Resistance

21. Light-dependent resistor (LDR) High resistance in the dark but a low resistance in light

23. Diode Allows current to flow in one direction only (from + to – in the direction of the “arrow)

25. Captain Jack Sparrow smoking a cigar

27. Two cowboys on a tandem

29. Two fried eggs in a frying pan

31. 3 wizards looking down a well

32. ac/dc Insulation and double insulation Earthing, fuses and circuit breakers

33. Brainiac – Cattle fence

34. Gather round!

35. Alternating current Current changes direction 50 times a second.

36. Fuse Thin piece of wire which melts if the current is too high If a fault develops, this thin piece of wire melts if the current is too high Circuit breakers are sometimes used instead

37. Earth wire Connects metal body of appliance to earth If a live wire comes loose, current flows to earth and blows the fuse

38. Double insulation Some appliances have no earth wire because they have a plastic outer case The plastic case acts as an extra layer of insulation around the wires

39. Reading! Read carefully pages 192-195 Answer the questions on both pages Finish for homework due Tuesday 13 th January