Electrical conductivity is a material's ability to conduct electric current. It is measured in siemens per meter. Materials with many movable charged particles like electrons or ions are good conductors of electricity, while insulators contain few mobile charges and conduct very little current. An experiment was described to test conductivity using a battery, lamp, wire and pencil lead. As the lamp was moved farther from the pencil lead, its brightness dimmed, showing that the pencil lead is a poor conductor over long distances due to few mobile charges in its material.

1. Electrical Conductivity
Prathomsueksa 5

3. Vocabulary

4. conductivity

5. conductor

6. electron

7. proton

8. battery

9. Structure
We use relative clauses to give
additional information about
something without starting another
sentence. By combining sentences
with a relative clause, your text
becomes more fluent and you can
avoid repeating certain words.

10. Recognize a relative clause
A relative clause—also called an
adjective or adjectival clause—
will meet three requirements.

11. -First, it will contain a subject and verb.
-Next, it will begin with a relative pronoun
[who, whom, whose, that, or which] or a
relative adverb [when, where, or why].
-Finally, it will function as an adjective ,
answering the questions What kind? How
many? or Which one?

12. The relative clause will follow one of
these two patterns:
Relative pronoun or adverb subject verb
+
Relative pronoun as subject verb

13. Example
Relative pronoun verb
Who continued to play video
games until his eyes were blurry
with fatigue.

14. Example
Relative pronoun
A conductor is a material which
contains movable electric
charges. verb

15. Example
Relative pronoun verb
That dangled from the one
clean bathroom towel.

16. Electrical Conductivity
Electrical conductivity is a material's ability
to conduct an electric current when an
electrical potential difference is applied
across it. It is also known as specific
conductance, and should not be confused
with conductance which is a property of a
component, whereas conductivity is a
property of the substance from which the
component is made.

17. The SI unit of electrical conductivity is the
siemens per metre (S/m). Conductivity is the
inverse of resistivity. The conductivity, σ, is
given in terms of current density, J, and electric
field strength, E, using the expression:
J = σE (Siemens /m)
J current density
σ conductivity
E electric field strength

18. Electrical conductor
A conductor is a material which contains
movable electric charges. In metallic
conductors such as copper or aluminum ,
the movable charged particles
are electrons . Positive charges may also be
mobile in the form of atoms bound in a
crystal lattice which are missing electrons,
or in the form of mobile ions,

19. such as in the electrolyte of a battery, or as
mobile protons in proton
conductors employed in fuel cells. In
general use, the term "conductor" is
interchangeable with "wire."Insulators are
non-conducting materials with few mobile
charges and which support only
insignificant electric currents.

20. Experiment

21. Materials
lamp wire battery
l

22. clear adhesive tape
razor
pencil lead

23. coins
spoon
key

24. Activity
1. Make a group of four ( but not now )
2. Let’s do the experiment by consulting with
your friends and draw a picture.
3. Come in front of the class to show your
experiment and conclude the experiment
please show your own song and dance follow
the song.

25. Procedures
Peel both sides of wire; the first side of
wire has to be longer than another side.

26. Connect the wire to the anode of
battery and bind another wire to the
base of the lamp.

27. Place the cathode of battery and the
base of the lamp on each side of the
pencil lead. Then, notice the
brightness of the lamp.

28. Gradually move the base of the lamp
follow the pencil lead ,and notice the
brightness of the lamp.

29. Conclusion
When we gradually move the base of the lamp
far from the pencil lead; the brightness of the
lamp will be dim up. If the space of the battery
and the lamp increase; the electric current that
passes through the pencil lead will be decrease
because the pencil lead is not a good conductor.