1. Who invented Vitamin A ?

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

2. Who invented CT scan ?

Answer: Hounsfield by Britain in 1973.

3. Who invented Helicopter ?

Answer:

Igor Sikorsky

4. Who invented Steam Engine (Piston)

Answer: Thomas Newcomen of Britain in 1712

5. Who invented Ball-Point Pen ?

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

6. Who invented X-ray ?

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

7. Who invented Nylon ?

Answer:

Wallace Carothers