1. Who invented Stethoscope ?

Answer: Laennec of French in 1819.

2. Who invented Ball-Point Pen ?

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

3. Who invented Open Heart Surgery ?

Answer:

Dr. Daniel Hale Williams

4. Who invented Radiocarbon ?

Answer:

Willard Libby

5. Who invented X-ray ?

Answer: W.K. Roentgen of Germany in 1895.

6. Who invented Steam Engine (Condenser)

Answer: James Watt of Britain in 1765

7. Who invented Bicyle ?

Answer: Kirkpatrick Macmillan of Britain.