1. Who invented Safety Pin ?

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

2. Who invented Circulation of blood ?

Answer: William Harvey of Britain in 1628

3. Who invented Vitamin D ?

Answer:

Edward Mellanby discovered Vitamin D while researching a disease called rickets in 1922

4. Who invented by Electric Lamp ?

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

5. Who invented Steam Engine ?

Answer: Thomas Savery of Britain in 1698

6. Who invented Machine Gun ?

Answer:

Helge Palmcrantz, Swedish inventor and industrialist

7. Who invented Atomic Bomb ?

Answer: J. Robert Oppenheimer of U.S.A. in 1945