Предмет: Физика, автор: Sasha9421

по проводнику с площадью сечения 50 мм^2 течет ток. Средняя скорость дрейфа свободных электронов 0,282 мм/с, а их концентрация 7,9 *10 ^ 27 м^-3. Найти силу тока и плотность тока в проводнике

Ответы

Автор ответа: Veronichka03

Дано:

S = 50 мм^2 = 5*10^-5 м^2

v = 0,282 мм/с = 2,82*10^-4 м/с

n = 7,9*10^27 м^-3

__________________________

I , j - ?

Решение:

I = envS = 1,6*10^-19 Кл*7,9*10^27 м^-3*2,82*10^-4 м/с*5*10^-5 м^2 = 17,8 А

j = I / S = 17,8 А / 5*10^-5 м^2 = 3.6*10^5 А/м^2

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DEVELOPMENT OF TELECOMMUNICATIONS
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2. Who built the first semaphore system?

3. What did semaphore as a communication system suffer from?

4. When was the first commercial electric telegraph constructed?

5. It used the deflection of needles to represent messages, didn't it?

6. What did Samuel Morse do on the other side of the Atlantic Ocean?

7. What happened on 27 July 1866?

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Smoke signals, visual telegraphy, skilled operators, to represent messages, the patented invention, transatlantic communication, to establish wireless communication, to investigate packet switching, to become widespread, orbiting satellites.

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b) commercial telephone services;

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