In which decade were the first successful diode and triode vacuum tubes invented?

1800s
1880s
1890s
1900s

The correct answer is D. 1900s.

The first successful diode vacuum tube was invented in 1904 by John Ambrose Fleming. The first successful triode vacuum tube was invented in 1907 by Lee De Forest.

A diode is a two-terminal electronic component that allows current to flow in one direction only. A triode is a three-terminal electronic component that allows current to flow in both directions, but can be controlled by a third terminal.

Vacuum tubes were the first electronic devices to amplify and rectify electrical signals. They were used in a wide variety of applications, including radio, television, and telecommunications. Vacuum tubes were eventually replaced by semiconductor devices, such as transistors, but they played a vital role in the development of modern electronics.

Option A: The 1800s was the century before the 1900s. It is unlikely that the first successful diode and triode vacuum tubes were invented in the 1800s, as vacuum tubes were not invented until the early 1900s.

Option B: The 1880s was the decade before the 1890s. It is unlikely that the first successful diode and triode vacuum tubes were invented in the 1880s, as vacuum tubes were not invented until the early 1900s.

Option C: The 1890s was the decade before the 1900s. It is unlikely that the first successful diode and triode vacuum tubes were invented in the 1890s, as vacuum tubes were not invented until the early 1900s.