1. + _ 5.2 Electric Field strength E

2. + _

3. QUESTIONQUESTION + _ -e

4. QUESTIONQUESTION F = E Q so E = …… F = E Q -e + _

5. QUESTIONQUESTION F = E Q so E = …… F = E Q -e + _

6. QUESTIONQUESTION F = E Q so E = …… F = E Q -e + _

7. QUESTIONQUESTION F = E Q so E = …… F = E Q -e + _

8. QUESTIONQUESTION F = E Q so E = …… F = E Q -e + _

9. QUESTIONQUESTION F = E Q so E = …… F = E Q -e + _

10. QUESTIONQUESTION F = E Q so E = …… F = E Q -e + _

11. QUESTIONQUESTION F = E Q so E = …… F = E Q -e + _

12. QUESTIONQUESTION F = E Q so E = …… F = E Q -e + _

13. Charge builds up in the cloud Electric field strength increases Electrons are pulled out of air molecules A massive discharge occurs heating and rapidly expanding the air Lightning:

14. slowly and safely ( thick copper strip ) Charge builds up in the cloud Electric field strength increases Electrons are pulled out of air molecules A massive discharge occurs heating and rapidly expanding the air Lightning: making a lightning strike less likely Using a Lightning conductor

20. Field strength (V/m) E = V d AB

21. Field strength (V/m) E = V d Force on a small + test charge Q in a field of strength E: F = E Q AB

22. Field strength (V/m) E = V d Force on a small + test charge Q in a field of strength E: F = E Q Work done by the field on Q in moving from A to B: W = F d AB

23. Field strength (V/m) E = V d Force on a small + test charge Q in a field of strength E: F = E Q Work done by the field on Q in moving from A to B: W = F d = EQ d AB

24. Field strength (V/m) E = V d Force on a small + test charge Q in a field of strength E: F = E Q Work done by the field on Q in moving from A to B: W = F d = EQ d AB But Pd V across the plates: V = W = Q

25. Field strength (V/m) E = V d Force on a small + test charge Q in a field of strength E: F = E Q Work done by the field on Q in moving from A to B: W = F d = EQ d AB But Pd V across the plates: V = W = Q EQd = Q

26. Field strength (V/m) E = V d Force on a small + test charge Q in a field of strength E: F = E Q Work done by the field on Q in moving from A to B: W = F d = EQ d AB But Pd V across the plates: V = W = Q EQd = Q

27. Field strength (V/m) E = V d Force on a small + test charge Q in a field of strength E: F = E Q Work done by the field on Q in moving from A to B: W = F d = EQ d AB But Pd V across the plates: V = W = Q EQd = Q Ed

28. Field strength (V/m) E = V d Force on a small + test charge Q in a field of strength E: F = E Q Work done by the field on Q in moving from A to B: W = F d = EQ d AB But Pd V across the plates: V = W = Q EQd = Q Ed so: E = V d

29. Field strength (V/m) E = V d Force on a small + test charge Q in a field of strength E: F = E Q Work done by the field on Q in moving from A to B: W = F d = EQ d AB But Pd V across the plates: V = W = Q EQd = Q Ed so: E = V d

30. Field strength factors: * Amount of CHARGE! * concentration of charge! Charge concentrates at points/tips So field lines concentrate there too.

31. + _ 5.2 Electric Field strength E