1. Who invented Safety razor ?

Answer: King Camp Gillette of U.S.A. in 1903

2. Who invented Ball-Point Pen ?

Answer: John J. Loud of U.S.A. in 1888

3. Who invented Vitamin D ?

Answer:

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

4. Who invented Microphone ?

Answer:

Emile Berliner invented the first microphone in 1876.

5. Who invented Submarine ?

Answer:

John Philip Holland

6. Who invented Neutron ?

Answer:

JAMES CHADWICK in 1932

7. Who invented Printing Press ?

Answer:

Johannes Gutenberg