1. Principles & Applications
Electricity
Principles & Applications
Sixth Edition
Richard J. Fowler
Chapter 1
Basic Concepts
© Glencoe/McGraw-Hill

2. INTRODUCTION
Work and Energy
Atoms
Ions
Charge

3. Work Requires Energy

4. The amount of work done equals the amount of energy used (converted).
Work (W)
consists of a force moving through a distance.
Energy (W)
is the capacity to do work.
Fifty joules of energy are required to do fifty joules of work.
The joule (J)
is the base unit for both energy and work.

5. Energy Conversion A cell converts chemical energy to electric energy.
A light bulb converts
electric energy to light
energy and heat energy.

6. Energy Quiz The _____ is the base unit of energy. joule
The symbol for the base unit of work is
the letter _____. J
The italicized upper-case _____ is the
symbol for energy. W
Doing forty joules of work requires
_____ joules of energy.
forty
A light bulb converts _____ energy into
_____ energy and _____ energy.
electric
light, heat

7. Particles
of the
Helium Atom

8. Protons (+ charge) + +

9. Protons (+ charge) + +
Neutrons (no charge)

10. Protons (+ charge) - + +
Neutrons (no charge) -
Electrons (- charge)

11. The electrons’ orbital paths are shown by the dashed lines.
The electrons orbit around the nucleus (neutron/proton cluster).
Protons (+ charge) - + +
Neutrons (no charge) -
Electrons (- charge)
The electrons’ orbital paths are shown by the dashed lines.

12. = Neutron +
= Proton -
= Electron
The two electrons are in the same shell even though they have different orbital paths. - + + -
HELIUM ATOM

13. Each electron stays in its own orbital path.
= Neutron +
= Proton -
= Electron - + +
Each electron stays in its own orbital path. -
HELIUM ATOM

14. Each electron stays in its own orbital path.
= Neutron - +
= Proton -
= Electron + +
Each electron stays in its own orbital path. -
HELIUM ATOM

15. Each electron stays in its own orbital path.
= Neutron +
= Proton -
= Electron - + +
Each electron stays in its own orbital path. -
HELIUM ATOM

16. Each electron stays in its own orbital path.
= Neutron +
= Proton -
= Electron - - + +
Each electron stays in its own orbital path.
HELIUM ATOM

17. Each electron stays in its own orbital path.
= Neutron +
= Proton -
= Electron - + +
Each electron stays in its own orbital path. -
HELIUM ATOM

18. Each electron stays in its own orbital path.
= Neutron +
= Proton -
= Electron - + +
Each electron stays in its own orbital path. -
HELIUM ATOM

19. Each electron stays in its own orbital path.
= Neutron +
= Proton -
= Electron - + +
Each electron stays in its own orbital path. -
HELIUM ATOM

20. Each electron stays in its own orbital path.
= Neutron +
= Proton -
= Electron - + +
Each electron stays in its own orbital path. -
HELIUM ATOM

21. Formation of Ions from Atoms

22. - - - - + 11 - - - - - - -
A SODIUM ATOM

23. - - - - - - - - + 17 - - - - - - - - -
AND A CHLORINE ATOM

24. FORMATION OF IONS - - - - - - - - - - - - - - - - - - - - - - - - - -+ 11 - - + 17 - - - - - - - - - - - - - - -
Sodium Atom
Chlorine Atom
FORMATION OF IONS

25. FORMATION OF IONS Free Electron - - - - - - - - - - - - - - - - - - -+ 11 - - + 17 - - - - - - - - - - - -
Free Electron - - -
Sodium Ion
Chlorine Atom
FORMATION OF IONS

26. FORMATION OF IONS - - - - - - - - - - - - - - - - - - - - - - - - - -+ 11 - - + 17 - - - - - - - - - - - - - - -
Sodium Ion
Chlorine Atom
FORMATION OF IONS

27. FORMATION OF IONS - - - - - - - - - - - - - - - - - - - - - - - - - -+ 11 - - + 17 - - - - - - - - - - - - - - -
Sodium Ion
Chlorine Atom
FORMATION OF IONS

28. FORMATION OF IONS - - - - - - - - - - - - - - - - - - - - - - - - - -+ 11 - - + 17 - - - - - - - - - - - - - - -
Sodium Ion
Chlorine Ion
FORMATION OF IONS

29. Static Charges

30. Force Between Electric Charges_
charge
charge _
charge _ _
charge _
charge
Like charges produce a repelling force.
When physically released, they repel each other.

31. Charged rod. (Many negative charges have been removed from the rod.)

32. Uncharged ball suspended on a thread
Uncharged ball suspended on a thread. (Equal number of negative and positive charges uniformly distributed.)
_ +_ +_
+_+_+_+
+_+_

33. Ball receives small induced charge as rod approaches
Ball receives small induced charge as rod approaches. (Note clustering of like charges on ball’s surface.) Weak force of attraction develops.
+_ +_ _
+++_+_ _
+_+_

34. More clustering of like charges and stronger attraction occurs as the rod is moved closer to the ball.
+ + +_ _ _
+ +_ _

35. Electrons are transferred from ball to rod when contact is made
Electrons are transferred from ball to rod when contact is made. Now, both ball and rod have a positive charge.

36. The ball is now repelled by the rod because of the like charges on the two objects.

37. Charge Quiz Electrons have a _____ electric charge. negative
Protons have a _____ electric charge.
positive
The _____ is electrically neutral.
neutron
The charge of a sodium ion is _____.
positive
A chlorine ion has a(n) _____ of electrons.
excess
Like charges _____ each other.
repel

38. REVIEW
Work and Energy
Atoms
Ions
Charge