câu hỏi  |
câu trả lời |
Who developed the theory of electromagnetic waves? What is another name for that theory? bắt đầu học
|
|
Maxwell developed the theory of electromagnetic waves. Another name for it is Maxwell's Equations or Classical Electromagnetism.
|
|
|
Whose ideas did Maxwell incorporate into his unified theory of electromagnetism? bắt đầu học
|
|
He incorporated the previous work of scientists like Michael Faraday (fields and lines of force), André-Marie Ampère (electrodynamics), and Carl Friedrich Gauss (electrostatics).
|
|
|
Who verified Maxwell’s ideas experimentally? bắt đầu học
|
|
Hertz verified Maxwell's ideas experimentally in the late 1880s.
|
|
|
What is a coherer? Who invented it? bắt đầu học
|
|
A coherer was an early radio wave detector consisting of a glass tube filled with metal filings. Its resistance decreased when exposed to radio waves. It was invented by Édouard Branly, and later improved by Oliver Lodge.
|
|
|
What did Tesla demonstrate in 1892? bắt đầu học
|
|
Tesla demonstrated a wireless radio-controlled boat.
|
|
|
Could the first radio transmit voice? bắt đầu học
|
|
No, the first radio systems transmitted signals using Morse code, not voice.
|
|
|
What did Popov demonstrate in 1895? bắt đầu học
|
|
Popov demonstrated a lightning detector, which was effectively the first radio receiver.
|
|
|
What can you say about Fessenden’s contribution to radio broadcast development? bắt đầu học
|
|
Fessenden made the first long-distance transmission of voice and music in 1906, which was a fundamental breakthrough for audio broadcasting.
|
|
|
What did Marconi patent in 1896? bắt đầu học
|
|
Marconi patented a system for wireless telegraphy (radio communication).
|
|
|
When and where did Marconi establish the first radio station? bắt đầu học
|
|
He established the first wireless telegraphy station in 1897 on the Isle of Wight, England.
|
|
|
How did Popov use the first radio receiver that he built in 1894? bắt đầu học
|
|
He used it to detect and record lightning strikes and atmospheric electricity.
|
|
|
How could Hertz transmit and receive electromagnetic waves in 1886? bắt đầu học
|
|
He used a spark-gap transmitter (a dipole antenna with a spark gap) to generate waves and a simple loop of wire with a small gap (a resonator) to detect them.
|
|
|
