1. Who invented Vitamin A ?

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

2. Who invented Vitamin K ?

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

3. Who invented Proton ?

Answer:

Ernest Rutherford

4. Who invented Stethoscope ?

Answer: Laennec of French in 1819.

5. Who invented Chloroform as anaesthetic ?

Answer: James Simpson of Britain in 1847.

6. Who invented Ball-Point Pen ?

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

7. Who invented Microphone ?

Answer:

Emile Berliner invented the first microphone in 1876.