General Knowledge

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

by
A. 1800s
B. 1880s
C. 1890s
D. 1900s
✅ The correct answer is option D.
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.

WTO, (World Trade Organization), WHO, (World Health Organization) and IDA (International Development Association) are ___ of General Assembly (UNO).

by
A. principal organs
B. other United Nations Organs
C. specialized agencies and other autonomous organization
D. they are independent agencies and not a part of UNO
✅ The correct answer is option C.