1. Who invented Machine Gun ?

Answer:

Helge Palmcrantz, Swedish inventor and industrialist

2. Who invented Submarine ?

Answer:

John Philip Holland

3. Who invented Periodic table ?

Answer:

Dmitri Mendeleev invented Periodic Table

4. Who invented Floppy disk ?

Answer: IBM in 1970

5. Who invented by Electric Lamp ?

Answer: Thomas Alva Edison of U.S.A. in 1879

6. Who invented Transformer ?

Answer:

Ottó Bláthy

7. Who invented DNA Structure ?

Answer: Crick(UK), Waston(US), Wilkins(UK) in 1951