Q22
In which decade were the first successful diode and triode vacuum tubes invented?
A.
1800s
B.
1880s
C.
1890s
D.
1900s
AnswerAnswer: Option D
Solution
Answer: Option D
Solution:
In 1904, John Ambrose Fleming invented the first practical electron tube called the 'Fleming Valve', which is a diode rectifier. In 1906, Lee de Forest invented the Audion later called the triode, which provided signal amplification.