Предмет: Физика, автор: kriakariz09

Могут ли газы быть проводниками,диэлектриками (ответ обосновать)? Приведите примеры

Ответы

Автор ответа: masyanyaaa

1

Ответ:

Проводни́к — вещество, проводящее электрический ток. Среди наиболее распространённых твёрдых проводников известны металлы, полуметаллы, углерод (в виде угля и графита) . Пример проводящих жидкостей при нормальных условиях — ртуть, электролиты, при высоких температурах — расплавы металлов. Пример проводящих газов — ионизированный газ (плазма) . Некоторые вещества при нормальных условиях являющиеся изоляторами при внешних воздействиях могут переходить в проводящее состояние, а именно проводимость полупроводников может сильно варьироваться при изменении температуры, освещённости, легировании и т. п.

К диэлектрикам относятся воздух и другие газы, стекло, различные смолы, пластмассы непременно сухие. Химически чистая вода также является диэлектриком.

Ряд диэлектриков проявляют интересные физические свойства.

К ним относятся электреты, пьезоэлектрики, пироэлектрики, сегнетоэластики, сегнетоэлектрики, релаксоры и сегнетомагнетики

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Предмет: Английский язык, автор: alia07jk

The City

The City occupies a site which was Norman London. It is a very small part of London (only one square mile). About ten thousand people live in the City but about 500,000 of them work there.
The City can still show the remains of its defensive wall and some other signs of the Roman time. In other parts of the City almost every stone, every wall, every house is Saxon or Norman or connected with some famous man, book or historical event.
The City of London was described by a Roman historian as a “busy emporium for trade and traders” and this description could have been applied to it at any time since then. The City still remains one of the most important commercial centres in the world.
All the principal streets lead to the heart of the City, which is represented by three buildings: the Mansion House, the Royal Exchange, the Bank of England.
The Mansion House is where the Lord Mayor lives. This is a big house built in 1739s53 which reminds us of Greek temple. The Lord Mayor also receives the guests of London there.
The Bank of England or as the Londoners call it “The Old Lady” is 250 years old and is a huge building seven storeys high. It is one of the most important banks in the world.
The Royal Exchange has been burnt down three times by fire and three times rebuilt. It is a place of business and public meetings.
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___________________
emporium - центр
temple - xpaм

I. The text is about ...
1) historical and business importance of the City.
2) Lord Mayor's residence.
3) principal business buildings of the City.
4) the territory and the population of the City.

II. Complete the sentence according to the text.
The City is a commercial and business part of London as ...
1) about ten thousand people live there.
2) all the principal streets lead to the heart of the City.
3) it is an area with a long history.
4) many offices, insurance companies, banks are concentrated there.

III. Choose the right sentence.
1) The City is a recently built part of London where one can't see any signs of ancient time.
2) The Mansion House reminds us of a Greek temple.
3) Many people live in the City but only a few of them work there.
4) Londoners call the Royal Exchange “The Old Lady” because it is a huge building seven storeys high.

IV. Find the wrong statement.
1) The Mansion House is a residence of Lord Mayor.
2) The Lord Mayor receives the guests of London in the Mansion House.
3) The Mansion House was built in the eighteenth century.
4) There are a lot of insurance companies and offices in the Mansion House.

V. Arrange the sentences according to the text.
1) The City of London was described by a Roman historian.
2) In the City one can see many signs of the Roman time.
3) The Royal Exchange has been burnt down three times by fire.
4) All the principal streets lead to the heart of the City.

1) 4, 1, 2, 3 2) 2, 1, 4, 3 3) 4, 2, 3, 1 4) 1, 2, 4, 3

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On a beautiful afternoon, in a year long gone, a big ship set out on its first voyage from England to America. It was a new ship called the “Titanic”.
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__________________
set out - отправился
called out – воскликнул

I. The text is about ...
1) a voyage from England to America.
2) brave sailors.
3) a new ship called the “Titanic” .
4) The courage of Miss Evans.
II. Choose tile right sentence.
1) The “Titanic” left America.
2) The “Titanic” went to England.
3) The “Titanic” left for America.
4) The “Titanic” sailed in the direction of England.

III. Complete the sentence.
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2) nobody to take care of the children.
3) no food and water.
4) not enough fresh air.

IV. Find the wrong statement.
1) Miss Evans was a young woman.
2) Miss Evans knew that the ship was sinking.
3) Miss Evans had no children.
4) Miss Evans got into another lifeboat.

V. Answer the question.
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2) She wanted to continue her voyage.
3) She gave her place in tile lifeboat to the children's mother.
4) She thought that the lifeboat could sink.

VI. Choose the title to the text.
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2) A Courageous Woman
3) In the Ocean
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__________________
to be upset – быть расстроенным

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3) She visits her friends.
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II. How many years is Jane’s fiance older than she is?
1) 20 years
2) 15 years
3) 10 years
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III. Who does Mrs. Ogden want her daughter to marry?
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