1. Who invented Vitamin A ?

Answer: Mc Collum and M.Davis of U.S.A. in 1913

2. Who invented Bakelite ?

Answer: Leo H. Baekeland of Belgium in 1907.

3. Who invented Transistor ?

Answer: Bardeen, Shockley & Britain of U.S.A. in 1948

4. Who invented Machine Gun ?

Answer:

Helge Palmcrantz, Swedish inventor and industrialist

5. Who invented Optical Fibre ?

Answer:

Indian-born American physicist Narinder Kapany

6. Who invented Diesel Engine ?

Answer: Rudoff Diesel of Germany in 1895

7. Who invented Ballistic missile ?

Answer: Wemher von Braun of Germany in 1944.