1. Who invented Safety Pin ?

Answer: Walter Hunt of U.S.A. in 1849

2. Who invented Vitamin K ?

Answer: Doisy Dam of U.S.A. in 1938.

3. Who invented Hydrogen bomb ?

Answer:

Edward Teller

4. Who invented Radar ?

Answer:

Sir Robert Watson-Watt

5. Who invented Machine Gun ?

Answer:

Helge Palmcrantz, Swedish inventor and industrialist

6. Who invented Floppy disk ?

Answer: IBM in 1970

7. Who invented Diesel Engine ?

Answer: Rudoff Diesel of Germany in 1895