1. Who invented Safety Pin ?

Answer: Walter Hunt of U.S.A. in 1849

2. Who invented Steam Engine (Piston)

Answer: Thomas Newcomen of Britain in 1712

3. Who invented Gramophone ?

Answer:

Emile Berliner in 1887.

4. Who invented Helicopter ?

Answer:

Igor Sikorsky

5. Who invented Air Conditioning ?

Answer:

Willis Carrier in 1902

6. Who invented Floppy disk ?

Answer: IBM in 1970

7. Who invented Laser ?

Answer:

Charles H. Townes