1. Who invented Helicopter ?

Answer:

Igor Sikorsky

2. Who invented Atomic Bomb ?

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

3. Who invented Refrigerator ?

Answer:

Oliver Evans in 1805

4. Who invented Blood Transfusion ?

Answer: Jean-Baptiste Denys of France in 1625.

5. Who invented Calculus ?

Answer: Newton of Britain in 1670.

6. Who invented Optical Fibre ?

Answer:

Indian-born American physicist Narinder Kapany

7. Who invented Stainless Steel ?

Answer: Harry Brearley of Britain in 1913.