Electrical conductivity

1. Electrical Conductivity Prathomsueksa 5

2. Vocabulary

3. conductivity

4. conductor

5. electron

6. proton

7. battery

8. 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.

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

10. - 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?

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

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

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

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

15. 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.

16. 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

17. 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,  

18. 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.

19. Experiment

20. Materials l battery wire lamp

21. clear adhesive tape razor pencil lead

22. coins spoon key

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

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

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

26. 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.

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

28. 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.