a) low resistance
b) high resistance
Current passes through conductors
a) easily
B) with great difficulty copper and silver are
a) common conductors
b) common insulators
Air, paper and plastics are
a) common insulators
b) common conductors
8.4.1.. Finish sentences: 1. Conductors have a low resistance.......2. Current passes through insulators with great difficulty.......3. Metals are common conductors.......4. To make insulators conduct,current of great value must be applied.......5. Carbon decreases its resistance when the temperature increases... 6. Metals have a positive temperature coefficient of resistance
Match the sides
| 1.Conductors are materials having a low resistance, 2. So the current easily passes through them. 3. The lower the resistance of the material the more current can pass through it. 4. The most common conductors are metals. 5. Silver and copper are the best of them. 6.The advantage of copper is that it is much cheaper than silver. 7. Thus copper is widely used to produce wire conductors. 8. One of the common functions of wire conductors is to connect a voltage source to a load resistance. 9. Since copper wire conductors have a very low resistance a minimum voltage drop is produced in them. 10.Thus, all of the applied voltage can produce current in the load resistance. 11. It should be taken into consideration that most materials change the value of resistance when their temperature changes. 12. Metals increase their resistance when the temperature increases while carbon decreases its resistance when the temperature increases. 13. Thus, metals have a positive temperature coefficient of resistance while carbon has a negative temperature coefficient. 14. The smaller is the temperature coefficient or the less the change of resistance with the change of temperature,the more perfect is the resistance material. 15. Materials having a very high resistance are called insulators. 16. Current passes through insulators with great difficulty. 17.The most common insulators are air, paper, rubber, plastics. 18.Any insulator can conduct current when a high enough voltage is applied to it. 19.Currents of great value must be applied to insulators in order to make them conduct. 20. The higher the resistance of an insulator the greater, the applied voltage must be. |
Answer the questions
1. What is the text about?
2. What materials are called conductors?
3. What is the advantage of copper compared with silver?
4. What is the most common function of wire conductors?
5. Why is a minimum voltage drop produced in copper conductors?
6. What is the relation between the value of resistance and the temperature in carbon?
7. What is the difference between conductors and insulators?
8. How does current pass through insulators?
9. What materials are commonly used to produce insulators?
10. What materials are commonly used to produce conductors?
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11. In what case do insulators conduct current?
12. How does resistance change when the temperature decreases?
X. Summarizing XI. Homework- read and translate. Learn the words and terms
| 1.Conductors are materials having a low resistance, 2. So the current easily passes through them. 3. The lower the resistance of the material the more current can pass through it. 4. The most common conductors are metals. 5. Silver and copper are the best of them. 6.The advantage of copper is that it is much cheaper than silver. 7. Thus copper is widely used to produce wire conductors. 8. One of the common functions of wire conductors is to connect a voltage source to a load resistance. 9. Since copper wire conductors have a very low resistance a minimum voltage drop is produced in them. 10.Thus, all of the applied voltage can produce current in the load resistance. 11. It should be taken into consideration that most materials change the value of resistance when their temperature changes. 12. Metals increase their resistance when the temperature increases while carbon decreases its resistance when the temperature increases. 13. Thus, metals have a positive temperature coefficient of resistance while carbon has a negative temperature coefficient. 14. The smaller is the temperature coefficient or the less the change of resistance with the change of temperature,the more perfect is the resistance material. 15. Materials having a very high resistance are called insulators. 16. Current passes through insulators with great difficulty. 17.The most common insulators are air, paper, rubber, plastics. 18.Any insulator can conduct current when a high enough voltage is applied to it. 19.Currents of great value must be applied to insulators in order to make them conduct. 20. The higher the resistance of an insulator the greater, the applied voltage must be. | 1. - , , 2. . 3. . 4. - . 5. . 6. , . 7. , . 8. . 9. , . 10. , . 11. , , . 12. , , , . 13. , , . 14. - , . 15. , , . 16. . 17. - , , , . 18. , . 19. , . 20. . |
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I. :.
Who is on duty today?
Who is absent?
What date is today?
What day of week is today?
II. :
Todays topic is. ONDUCTORS AND INSULATORS :
to recognize new words and expressions,
to understand their meaning and operate by them discussing the text;
to identify main ideas and details from the text;
to participate in common conversational exchanges on the topic of today's lesson.
III. :
The knowledge of this topic will increase your outlook and knowledge of some interesting facts about metals, their place in the life, as future specialists you must be well-educated, cultured people. This information will help you in your future profession
IV. .
Grammar tests:
V) :
Watch the short video. Try to understand and answer the questions
VI) O :
I'll check your homework.
t) .
VII.
VIII.
1 Introduction with a new words
2 Exercises
3. Introduction with a new topic
4 Exercises
5. Reading the text
IX Homework
X.Summarizing
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Read and remember
